When Leonard and Sheldon encounter a young woman crying on the curb, Leonard invites her to dinner....

Celebrating the 100th episode of US sitcom The Big Bang Theory, Rick Edwards travels to the Hollywoo...

Celebrating the 100th episode of The Big Bang Theory, Rick Edwards looks back at some of the US sitc...

Brilliant physicist roommates Leonard and Sheldon meet their new neighbor Penny, who begins showing...

Leonard volunteers to sign for a package in an attempt to make a good impression on Penny, but when...

Leonard asks a woman out after he finds out that Penny is seeing someone.

Sheldon's getting fired forces him to explore what life has to offer outside physics, leaving Leonar...

Fearing he's wasting his time on Penny, Leonard ends up making a connection with Leslie.

Penny hosts a Halloween party, putting Leonard, Sheldon, Wolowitz, and Koothrappali through a new te...

With Wolowitz AWOL with one of her friends, Penny's recruited to fill in for him on the guys' Halo t...

Raj's parents set him up on a blind date, but just when he discovers he can talk to her, she shows i...

When they're invited to present at a physics conference, Sheldon's reluctance to share the credit le...

Leonard and Sheldon each lie to avoid seeing Penny's concert, but Sheldon's is a bit too complicated...

With his friends knowing how sour he acts when sick—and avoiding him as a result—Sheldon is nursed b...

With Sheldon rattled over meeting Dennis, a 15-year-old physicist who's smarter than he, Leonard hel...

Sheldon finds himself booted from the gang's Physics Bowl team and replaced with Leslie, so he forms...

When delivery of another collectible leads to Penny's lashing out at Leonard, he decides it's time t...

The rest of the gang fall for Sheldon's twin sister, and Leonard's plan to win her heart is derailed...

Penny wants to throw a surprise party for Leonard, but Sheldon's indulgence at an electronics store...

Penny's break-up spurs Leonard to summon the courage to ask her out, and each goes to Sheldon for ad...

Penny's first date with Leonard goes awry; Penny finds Sheldon to be an unwilling confidant.

A jealous Leonard reacts to Penny's new guy by rebounding with Leslie.

Sheldon creates a monster when he introduces Penny to online gaming.

Raj gets an inflated ego and makes a play for Penny after being referenced in a magazine article.

Leonard and his friends stage an intervention to force Sheldon to face his fear of driving.

Sheldon and the gang are confused when a young grad student is attracted to him.

When Sheldon bans Penny from the apartment for numerous minor infractions, she decides to retaliate.

Leonard inadvertently steals away the new woman Wolowitz thinks is the love of his life.

Sheldon is thrilled when Leonard starts dating a woman who meets Sheldon's stringent standards.

Leonard asks Penny for advice when his new relationship starts moving too fast.

Penny starts dating Leonard's handsome colleague; Leonard and his friends are tortured by Sheldon's...

Penny's criticism of Wolowitz's romantic life pushes him into depression and AWOL for a fighting rob...

Sheldon creates a scientific procedure for making friends.

Sheldon's solution to Penny's financial difficulty leads to a confrontation between Leonard and Penn...

Leonard and Penny are drawn together after a disastrous visit from Leonard's mother.

A paintball game leads to a fight between Sheldon and Penny, and romance for Leslie and Wolowitz.

Leonard, Sheldon and Wolowitz are ecstatic to learn that a famous science-fiction actress (Summer Gl...

Penny's home business turns into a complete nightmare when Sheldon takes over.

Penny squares off with a new beautiful female neighbor who may become the building's "new Penny."

A fellow comic book enthusiast's hitting on Penny leads to Leonard and Howard going to a bar's Ladie...

Leonard and Koothrappali escort a heartbroken Wolowitz to Las Vegas, and Sheldon becomes locked out...

Penny's second date with Stuart sees her making a comment that gives Leonard new hope for a relation...

The guys' plan to work over the summer at the North Pole makes Penny revaluate her feelings for Leon...

When Sheldon learns the guys tampered with his expedition data he got from the arctic, he leaves to...

Leonard and Penny struggle to recover from an awkward first hookup while Sheldon and Howard stake th...

Howard and Raj visit a Goth nightclub to pick up women while Sheldon attempts to build a better Penn...

Raj must find a new job or be sent back to India, but Sheldon has a solution, which leaves Leonard a...

After overhearing that Wil Wheaton is entering a trading-card competition, Sheldon decides to enter...

Sheldon becomes Leonard's teacher in order to understand football, while an incident with flying a k...

A squabble between Leonard and Penny sees Sheldon playing mediator, though out of his own incovenien...

With Leonard, Howard and Raj away camping in the desert, an injured Penny has only Sheldon to rely o...

After he's humiliated on National Public Radio, Sheldon vows to destroy Kripke, while Wolowitz tries...

Penny gets help from Sheldon in order to understand what Leonard's work is, while Wolowitz develops...

A Christmas visit from his mother has Leonard discovering she's kept a lot of news from him that she...

Leonard is aghast to find out a secret of Penny's: she believes in psychics. Meanwhile, Sheldon trie...

When their apartment is robbed, Leonard and Sheldon turn to their friends to create a state-of-the-a...

Sheldon's search for the answer to a physics problem leads him to work at the Cheesecake Factory wit...

Leonard can only bring one guest on a trip to see CERN's Large Hadron Collider (the world's largest...

Sheldon winds up in traffic court when he gets a ticket because of Penny.

When the guys find a ring from "The Lord of the Rings" at a garage sale, it threatens to tear them a...

Sheldon's friends come to his aid when his fear of public speaking stands between him and a coveted...

A fight between Leonard and Penny threatens their relationship, while Sheldon battles Wil Wheaton in...

When Leonard and Penny aren't speaking, Sheldon goes to extremes to keep them both happy.

Leonard and Sheldon compete for the attention of a famous female physicist.

Leonard tells Penny about how he met Sheldon for the first time...and what happened to the elevator.

While Penny worries that dating Leonard has ruined her for normal guys, Wolowitz and Koothrappali se...

Penny tags along on Sheldon's first ever date; Wolowitz finds a new use for a robotic arm.

Realizing he will not live long enough to download his consciousness into a robot body, Sheldon trie...

The guys are concerned as Sheldon searches for an alternative to human companionship.

An embarrassing secret of Wolowitz's comes to light, while Sheldon and Raj have a small war at work.

Leonard realizes he’s the only one without a girlfriend, while Sheldon wants to get rid of his.

Leonard keeps an affair a secret from Sheldon, Howard and Raj.

Sheldon's answers during an FBI interview put Wolowitz's security clearance in jeopardy.

While the guys camp in line for a long-awaited movie screening, Penny and Bernadette invite Amy to h...

Penny asks Leonard to lie to her father, while Howard, Raj and Bernadette pull an all-nighter at a t...

Amy finds she has sexual feelings for Penny's ex, while Koothrappali and Wolowitz try to prove who w...

The guys find a "super" use for Penny's new boyfriend, Zack, when they enter a costume contest as th...

Leonard's idea for a smartphone app derails his friendship with Sheldon.

Bernadette runs into her ex-boyfriend while attending a science event with Wolowitz.

Hoping it will make him a better teacher, Sheldon has Penny give him acting lessons. Raj has fantasi...

A wealthy donor to the university makes Leonard consider how far he's willing to go for the sake of...

As Wolowitz contemplates taking things with Bernadette to the next level, Leonard rekindles his rela...

Sheldon becomes concerned when everybody begins to hang out at Raj's apartment and discovers Leonard...

Sheldon is baffled by Wolowitz's magic trick. Meanwhile, Leonard realizes dating Priya may make it i...

Sheldon's online-game account is hacked by Todd Zarnecki, who then proceeds to steal all his items p...

Sheldon and Amy decide to start several rumors about the others as a test. Meanwhile, Howard takes h...

When Leonard spends too much time in the shower with Priya, Sheldon charges Leonard with two violati...

Raj attempts to cure his social anxiety disorder while Penny uses Bernadette to spy on Leonard and h...

When Howard finally breaks the news to his mom that he's engaged to Bernadette, it lands her in the...

When Bernadette receives her PhD, Wolowitz feels emasculated. Raj and Leonard swap places and Penny...

Penny is worried with how damaged her friendship with the guys will be in the aftermath of her sleep...

A fight between Sheldon and Penny leaves Amy caught in the middle, while Leonard tries to spice up h...

Leonard and Amy get to know each other better, while Howard and Bernadette spend the weekend with Mr...

Penny plays Matchmaker for Raj, which results in him finding a girl he is comfortable talking to.

Sheldon and Leonard get invited to a party at Wil Wheaton's house, and Howard gets an out-of-this-wo...

Sheldon's mother, Mary Cooper, comes to visit, but Sheldon is annoyed that she also spends time with...

A cute comic book artist puts Leonard and Priya’s relationship to the test, while Sheldon tries to s...

Amy becomes heartbroken when she discovers that Penny and Bernadette went wedding dress shopping wit...

Leonard and Penny try hanging out as friends on a 'non-date', but end up purposely ruining each othe...

When Stuart asks Amy out on a date, Sheldon must confront his feelings and consider where his relati...

Leonard must face his fears after being contacted by his high school tormentor.

Sheldon gets in trouble with Amy when he isn't impressed by her recent accomplishment, and Howard mu...

Leonard, who broke up with Priya, asks Penny out to a spur-of the-moment romantic dinner for two, an...

Leonard and Penny deal with the idea of starting a relationship again and Raj finally finds a "woman...

Sheldon's selfish demands force Leonard to reconsider their friendship. Meanwhile, Wolowitz tries to...

When Sheldon is forced to take his vacation, he goes to work with Amy in her neurobiology lab.

Sheldon battles Kripke for a coveted office at the university. Penny receives a very unusual gift fr...

Sheldon becomes agitated when his regular barber is out sick. Astronaut training causes Howard to re...

Sheldon must choose between joining Amy at her aunt's birthday party or playing videogames all weeke...

Penny buys Leonard and Sheldon “Star Trek” collectibles as a thank-you, leading Sheldon to be haunte...

When Wolowitz gets to work with Stephen Hawking, Sheldon is willing to do anything to meet his hero.

After the guys throw Howard a bachelor party, Bernadette reconsiders marrying him after learning abo...

When NASA moves up Howard's mission, he must face his fears and Bernadette's dad, thus putting the w...

The fifth season ends with Howard and Bernadette deciding to get married before his NASA mission, ca...

With his friends on dates, Raj must face his loneliness. Also, Wolowitz is caught in an argument bet...

When Sheldon learns that Penny is thinking about breaking up with Leonard, he tries to intervene. Me...

Amy feels threatened when Sheldon hires a young female assistant, and the pressure of being in space...

When Wolowitz returns from space, he doesn’t get the hero’s welcome he expected. Meanwhile, Game Nig...

The gang celebrates Halloween at Stuart’s comic book store. Meanwhile, Leonard seduces Penny with sc...

Sheldon’s relationship with Stephen Hawking is threatened over a game of “Words with Friends,” and P...

Wolowitz struggles with moving out of his mother’s house. Meanwhile, Sheldon is caught in the middle...

Raj and Howard try to to figure out why Sheldon disappears at 2:45 every afternoon; jealousy arises...

When the University reassigns Sheldon’s parking spot to Wolowitz, their fight affects the whole gang...

When Amy gets sick, Sheldon tries to nurse her back to health; Wolowitz and his father-in-law plan a...

During a Dungeons and Dragons game, Sheldon revisits Christmas memories; Amy, Penny and Bernadette l...

When Sheldon is accused of sexual harassment, he ends up getting Raj, Leonard and Howard in trouble.

As the guys don costumes and go on a road trip to a comic book convention, the ladies decide to stay...

Sheldon faces a crisis of confidence when he is forced to work with his nemesis, Barry Kripke; Raj a...

A fight between Sheldon and Leonard impacts Amy and Penny's living arrangements; while Howard is awa...

The guys search for a perfect Valentine's Day gift for their significant others; Stuart and Raj host...

After a bad date, Koothrappali decides to never leave his apartment; Penny's acting skills impress S...

Leonard, Sheldon and Howard give lectures on science to junior high students. The girls ditch work t...

Howard considers whether or not he should open a letter from his father; Penny and Leonard host a "g...

The girls get involved when Leonard, Sheldon and Raj compete for tenure at the University.

Amy tries to help Sheldon get over his compulsive need for closure when one of his favorite TV shows...

Leonard and Sheldon hire the host (Bob Newhart) of their favorite childhood TV show to perform; Bern...

A date between Raj and Lucy takes both of them out of their comfort zones. After a trip to Las Vegas...

When Leonard receives an exciting opportunity to work overseas, Penny and Sheldon are thrown for a l...

With Leonard away, Sheldon and Penny spend quality time together sharing intimate secrets. Also, Wol...

Leonard and Sheldon's friendship is tested; Howard's latest foray into helping his mother has some d...

When the entire gang competes in a scavenger hunt designed by Raj, it brings out the best - and wors...

Sheldon gets mad at Amy for ruining one of his favorite movies, Raj and Stuart try to make their onl...

Amy starts working at Caltech which causes friction with Sheldon. Howard agrees with Sheldon who men...

Sheldon's latest scientific breakthrough leaves him feeling like a fraud; a romantic gesture between...

Sheldon seeks payback when Arthur "Professor Proton" Jeffries asks Leonard for help on a project ins...

When a mistake comes to light, Sheldon makes Leonard walk a mile in his shoes; Penny decides to conf...

Sheldon protests when the gang drags him to Mrs. Wolowitz’s house for Thanksgiving. Meanwhile, Penn...

Leonard has to deal with the fallout of disproving Sheldon's new scientific discovery. Raj spends a...

While Sheldon is at home in Texas, the rest of the gang realizes how much he has changed their lives...

When Penny’s big acting break on NCIS is a bust, Leonard struggles to help her, which results in Pen...

Sheldon tries to relax after he is forced to take a vacation. Meanwhile, Leonard struggles to be sup...

After the guys can’t get Comic-Con tickets, Sheldon tries to hold his own convention and winds up sp...

Sheldon and Amy take a train ride to Napa Valley with Howard and Bernadette on Valentine's Day. Leon...

Leonard buys a dining room table and it causes Sheldon to reevaluate the changes in his life. Meanwh...

After arguing with Sheldon, Howard tries to make amends by taking him to NASA headquarters in Housto...

When Sheldon visits his Mom in Houston, he is forced to confront a new reality. Meanwhile, Raj’s ‘Mu...

While Raj is wracked with guilt when he tries to date two women at once, Penny wrestles with whether...

Sheldon faces a personal crisis after deciding he’s wasting his time with string theory. Meanwhile,...

To prepare for a date with Emily, Howard acclimates Raj to horror movies. Penny and Sheldon are upse...

As the gang celebrates Star Wars Day, Sheldon has difficulty dealing with the recent death of Arthur...

A bad day causes Penny to reevaluate her life choices – including Leonard. Meanwhile, Howard and Ber...

Sheldon get upset about his career, the destruction of the comic book store and Leonard and Penny's...

Leonard and Amy make an unexpected trip to Arizona to fetch Sheldon; Penny interviews for a job at B...

Sheldon is forced to teach a class as a Junior Professor and Howard decides to enroll in it. Meanwhi...

Wolowitz feels nervous when he is asked to throw the first pitch at a Los Angeles Angels game. Penny...

Raj's honesty comes back to haunt him when his new girlfriend is unfriendly to Penny. The guys think...

The girls head to Las Vegas for some weekend fun, while the guys try to invent something cool, but o...

Sheldon and Raj test whether they could survive a dark-matter research expedition in a salt mine by...

The guys try to help Penny out of an awkward work dilemma, when a smitten doctor shows up at her doo...

The girls decide to re-enact their high school proms with the guys. While Sheldon feels under pressu...

When Leonard gets minor surgery on his nose, Sheldon is the one in need of sympathy. Meanwhile, Raj'...

While Sheldon says a tearful goodbye to the final installment of "Fun with Flags", Leonard, Howard a...

Leonard and Howard turn to Raj for help in dealing with a work emergency when they nearly come to bl...

Howard tries to distract Raj, who is anxiously awaiting data from a space probe he helped launch. Me...

When Sheldon becomes stuck in a rut with his work, the gang tries to help him by raising his stress...

Leonard and Sheldon publish a paper which is widely accepted except for comments from an internet tr...

Howard receives some shocking news as everyone prepares for the reopening of Stuart’s comic book sto...

As a joke, Sheldon and Penny try an experiment designed to make participants fall in love. Meanwhile...

A trip to the pet store ends in a fight after Amy learns Sheldon has applied for a one-way mission t...

Friction ensues when a magazine fails to mention Leonard in an article about the paper he co-wrote w...

When Leonard and Sheldon are invited to speak at UC Berkeley, they take a detour to try to meet an i...

When Sheldon and Amy build a blanket fort, they come to major crossroads in their relationship. Also...

When Raj is asked to create a message in case a NASA mission discovers alien life, the guys fight ov...

Howard questions his engineering abilities when he and Sheldon can’t get a toy drone to fly. Meanwhi...

Personalities collide when Sheldon and Leonard’s mothers finally meet. Meanwhile, Howard finally dec...

As Sheldon presses Leonard and Penny to set a wedding date, he encounters major changes in his own r...

After driving to Vegas to get married, Penny struggles with Leonard’s confession that he kissed anot...

Leonard confronts the woman he kissed on the North Sea in an attempt to set Penny's mind at ease. Al...

The guys' science skills are put to the test when they get a flat tire during Leonard's bachelor par...

Sheldon learns of an impending change in his living arrangements and decides to revert back to 2003,...

The guys take a fencing lesson from Barry Kripke and Sheldon finds himself in an awkward position wh...

In the midst of a nation-wide helium shortage, Sheldon and Leonard take desperate measures to get th...

Wil Wheaton interviews Sheldon for a Star Trek documentary where he reveals the ring and his plan to...

Sheldon, Wolowitz and Koothrappali post an online advertisement to find Sheldon a new girlfriend. Al...

Sheldon and Amy try hanging out as friends when they spend Thanksgiving together at the aquarium. Al...

Sheldon has a revelation when he realizes why a song was stuck in his head. Also, Amy invites Dave o...

After more than five years of dating, Sheldon and Amy spend their first night together. Also, Leonar...

Penny gets more than she bargained for when Leonard agrees to meet with a psychiatrist on her behalf...

After having to deal with a sick Sheldon, Leonard, Penny and the gang try to treat themselves to a S...

Meemaw meets Amy, but it isn't all roses. Meemaw seems to have an axe to grind with her. Sheldon com...

Sheldon and Amy host a live Valentine's Day episode of Fun with Flags, Leonard and Penny grapple wit...

When the gang finds out about Bernadette’s pregnancy, they celebrate by singing karaoke. Also, Bern...

After more than nine years together, the gang finally celebrates Sheldon’s birthday, surprising him...

Leonard, Sheldon, and Wolowitz run into problems when they file for a patent for their infinite pers...

Amy is shocked at a revelation from Sheldon after she buys him a new laptop. Also, Koothrappali sell...

Sheldon spills a secret of Leonard’s when the two take a weekend cabin trip with Penny and Amy. Als...

Everyone must choose sides when a small argument between Leonard and Sheldon erupts into a heated f...

The gang goes to a wine bar and runs into Penny’s old boyfriend, Zack. Also, Bernadette gets stuck s...

Sheldon hires Stuart to spend the day with Amy when he’d rather go to a movie screening. Also, Leona...

Chaos ensues when Leonard’s recently divorced parents, Alfred and Beverly, and Sheldon’s devoutly re...

After Sheldon’s mother and Leonard's father share an evening together, everyone deals with an awkwar...

Colonel Williams, an Air Force representative from the Department of Material Command sits down to t...

Tensions rise when the boys struggle to complete their government project on time and Sheldon tries...

When Amy’s apartment floods, she proposes a “cohabitation experiment” with Sheldon. Also, Howard and...

Leonard and Penny must separate a quarreling Sheldon and Amy when their cohabitation does not go as...

Penny is surprised to learn she has fans of her performance in "Serial Ape-ist" when she attends Van...

In order to continue living with Sheldon, Amy lies to him about repairs being made to her apartment...

After a successful experiment combining their genes, Sheldon will stop at nothing to convince Amy th...

When Bert, a Caltech geologist, wins the MacArthur Genius fellowship, Sheldon is overcome with jealo...

Sheldon and Leonard try to divvy up their shared belongings, but can’t agree on anything. Also, Koot...

Howard and Bernadette welcome their new baby and Sheldon and Amy celebrate Amy’s birthday.

Sheldon and Amy visit Leonard and Penny for the first time since the holidays and share details abou...

When Penny feels that Leonard is taking her for granted, she decides to go on a spa weekend with Amy...

Sheldon beta-tests an MIT invention after hearing it can help him read people’s emotions. Also, Leon...

Leonard and Wolowitz try to distract Sheldon when he slows the progress of their guidance system. Al...

Sheldon and Amy have their first fight since moving in together, and Koothrappali is shocked at the...

With Koothrappali cut off from his father’s fortune, he appoints Sheldon to help him get out of debt...

When Raj moves out of his apartment, Leonard and Penny offer him Sheldon's old room.

Leonard, Penny and Raj adjust to their new living arrangement, and Sheldon takes an interest in Amy’...

Sheldon pushes himself to the limit when he collaborates on projects with Leonard and Wolowitz as we...

Howard and Bernadette have a hard time leaving Halley in day care when Bernadette returns to work. A...

Leonard isn’t thrilled when Penny considers taking a new job offered by her ex-boyfriend, Zack.

After Leonard, Sheldon and Wolowitz celebrate the completion of the top secret air force project, th...

The gang is concerned when Sheldon’s former admirer, Dr. Ramona Nowitzki, resurfaces while Amy is aw...

In the eleventh season opener, Amy gives Sheldon an answer to his proposal while Howard and Bernadet...

Leonard angers the university – and the entire physics community – after he gives an embarrassing in...

Sheldon and Amy struggle with picking a wedding date, which stresses out Sheldon and causes him talk...

As Howard worries about fatherhood, he and Sheldon bond when they jointly assemble a model rocket. M...

Sheldon and Raj confide in Bernadette when they can't handle Amy and Howard working together on a sc...

Sheldon goes head-to-head with Wil Wheaton for the role of the new Professor Proton. Also, Penny ste...

Sheldon and Bert collaborate on a research project, despite Sheldon’s embarrassment. Also, Penny and...

Leonard and Howard are furious after they learn Sheldon went to work with the military behind their...

Sheldon tries to teach the guys a lesson after they cut him out of a potentially valuable Bitcoin in...

Sheldon and Amy try to eliminate stress from wedding planning by applying math to the process. Also,...

Raj and Howard's feud continues as the gang plan Halley's first birthday party. Sheldon's surprise f...

Sheldon and Amy try to pick their Best-Man and Maid of Honor by experimenting on the gang.

When Sheldon kicks Amy out to work solo, she and Leonard bond during a series of science experiments...

Raj finds himself in the middle of domestic drama when he learns the woman he's dating, has a very u...

Leonard's book raises questions, and Amy guest stars on the new Professor Proton show.

When Bernadette won't go into labor, the gang tries different tactics to get things started. Also, H...

Leonard jumps through hoops to help secure the perfect wedding venue for Sheldon and Amy. Also, Bern...

Bill Gates visits Penny's work, and the gang schemes to meet him. Hilarity ensues. Meanwhile, Sheldo...

When Leonard learns Sheldon is the president of the tenants association, he decides to run against h...

A brilliant but reclusive scientist, Doctor Wolcott, invites Sheldon to his cabin in the middle of n...

Sheldon’s comic book store experiences changes when writer Neil Gaiman puts Stuart’s store on the ma...

Sheldon goes to Vegas to win money for science. Also, Penny and Bernadette take Amy wedding dress sh...

When Sheldon learns that his mother won’t attend his wedding unless he invites his brother, Georgie,...

When Amy's parents and Sheldon's family arrive, everybody is focused to make sure all wedding arrang...

Sheldon and Amy's honeymoon runs aground in New York. Penny and Leonard discover they are uncomforta...

Sheldon and Amy drive themselves crazy trying to figure out what 'perfect gift' Leonard and Penny ga...

The Wolowitzes' life gets complicated when Stuart starts bringing his new girlfriend home. Also, Pen...

When Sheldon won't tell anyone why he's never mentioned his childhood best friend, Leonard takes mat...

When Amy doesn’t have time to work on super-asymmetry, Sheldon goes to great lengths to ensure she’s...

When Howard dresses up as Sheldon for Halloween, Sheldon seeks retaliation at Leonard and Penny's Ha...

Leonard is caught between a rock and a hard place when he's responsible for distributing extra grant...

Sheldon tries to bond with Amy's father, but when Howard lures Mr. Fowler away with magic tricks, Sh...

Sheldon and Amy are devastated after learning from a Russian paper that Super Asymmetry has already...

Sheldon and Amy are still down about their theory being disproven, but a VHS tape from Sheldon’s pas...

Penny and Leonard organize a paintball game that results in mayhem when Sheldon is jealous of Amy. A...

Penny runs into her ex-boyfriend, Zack, who invites her and Leonard to a dinner to meet his newlywed...

Sheldon and Amy are thrilled when their super asymmetry theory is proven by two physicists, until th...

Sheldon is thrilled to help Bernadette and Wolowitz navigate bureaucratic paperwork, until he discov...

Penny tries to seduce an abstaining Leonard to ruin his "donation" for her ex-boyfriend, Zack, and h...

The gang finds out Wil Wheaton hosts a celebrity Dungeons and Dragons game involving William Shatner...

When Penny and Bernadette go to San Diego for a pharmaceutical sales convention, Wolowitz is in char...

When competitors Pemberton and Campbell charm America on a publicity tour, Sheldon and Amy try to br...

The concept of what it would mean for women everywhere if Amy were to win a Nobel Prize causes Amy t...

Raj is worried people won’t take him seriously in his own field after publishing a paper that sugges...

Kripke has proof that Dr. Pemberton plagiarized his thesis in college, and Sheldon and Amy aren't su...

Leonard is pleasantly surprised when Beverly comes to visit and she's genuinely kind to him, until h...

Sheldon and Amy await big news. Meanwhile, Penny and Leonard have some big news of their own. Also,...

Johnny Galecki and Kaley Cuoco will lead fans on a trip down memory lane, sharing some of the best-k...