The Big Bang Theory

Created by writer/producers Chuck Lorre (of Two and a Half Men) and Bill Prady (of Gilmore Girls) comes The Big Bang Theory, a sitcom that shows what happens when hyperintelligent roommates/physicists Sheldon and Leonard meet Penny, a beautiful woman moving in next door--and realize they know next to nothing about life outside of the lab. Rounding out the crew are the smarmy Wolowitz, who thinks he's as sexy as he is brainy, and Koothrappali, who suffers from an inability to speak in the presence of a woman.
The show distinguishes itself by being unafraid to toss scientific references and technobabble into an otherwise standard sitcom, even employing a physicist to keep things accurate. In doing so, it allows Sheldon and Leonard to do for science what Frasier's Crane brothers did for fine dining, art, and opera.
Theme Song: "The History of Everything" by Barenaked Ladies

The Big Bang Theory - Season 5 Episode 11

Leonard confronts his fears when he's contacted by a bully who tormented him in high school

The Big Bang Theory - Season 5 Episode 10

Sheldon becomes jealous when Stuart from the comic-book store asks Amy out on a date, and Sheldon's forced to reconsider his relationship with Amy

The Big Bang Theory - Season 5 Episode 9

Leonard and Penny attempt to hang out alone; and Sheldon tries to overcome his fear of birds

The Big Bang Theory - Season 5 Episode 8

Amy is crushed when Bernadette and Penny go shopping for wedding dresses without her

The Big Bang Theory - Season 5 Episode 7

Leonard feels threatened when a charming comic-book artist comes between him and Priya; and Sheldon is determined to scare his friends on Halloween

The Big Bang Theory - Season 5 Episode 6

Sheldon's mom visits, and he competes for her attention, which seems more focused on his friends.

The Big Bang Theory - Season 5 Episode 5

Leonard and Sheldon attend a party at the home of Sheldon's nemesis, Wil Wheaton (in a cameo along with Brent Spiner).

The Big Bang Theory - Season 5 Episode 4

Raj meets a woman with whom he's able to talk.

The Big Bang Theory - Season 5 Episode 3

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

The Big Bang Theory - Season 5 Episode 2

Penny and Sheldon clash, and Amy is caught in the middle of their battle; and Leonard looks for ways to keep his long-distance romance with Priya alive.

The Big Bang Theory - Season 5 Episode 1

In the fifth-season opener, Penny hits a low point when she realizes what she's done by sleeping with Raj; and Sheldon becomes the leader of the paintball team

The Big Bang Theory - Season 4 Episode 24

In the fourth-season finale, Raj moves in with Sheldon when Leonard and Priya's "Star Trek" bedroom fantasy is too much for him; and the guys tease Howard when Bernadette gets her PhD, making Howard the only one without ...

The Big Bang Theory - Season 4 Episode 23

Howard finally tells his mother that he's marrying Bernadette, and the news puts her in the hospital.

The Big Bang Theory - Season 4 Episode 22

Raj makes an attempt to cure his phobia of talking to women; and Penny spies on Leonard and Priya with the help of Bernadette.

The Big Bang Theory - Season 4 Episode 21

Priya uses her legal expertise to rip apart Sheldon's roommate agreement, and the women take the flustered Sheldon out dancing

The Big Bang Theory - Season 4 Episode 20

Sheldon and Amy spread gossip as part of an experiment; and Howard and Bernadette's relationship gets serious. Physicist Brian Greene has a cameo

The Big Bang Theory - Season 4 Episode 19

The guys become sleuths to find out who hacked Sheldon's online-game account

The Big Bang Theory - Season 4 Episode 18

Leonard is forced to choose between Penny and his new girlfriend, Priya; Howard's magic trick drives Sheldon crazy.

The Big Bang Theory - Season 4 Episode 17

Sheldon is upset when he realizes Leonard is the center of their group of friends.

The Big Bang Theory - Season 4 Episode 16

Wolowitz considers taking things with Bernadette to the next level; Leonard and Raj's sister rekindle their relationship.

The Big Bang Theory - Season 4 Episode 15

A wealthy donor makes Leonard question what he is willing to do for science.

The Big Bang Theory - Season 4 Episode 14

Sheldon takes acting lessons from Penny in hope of becoming a better teacher; Koothrappali fantasizes about his friend's girlfriend.

The Big Bang Theory - Season 4 Episode 13

Bernadette runs into her ex-boyfriend (Rick Fox) while attending a science event with Wolowitz.

The Big Bang Theory - Season 4 Episode 12

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

The Big Bang Theory - Season 4 Episode 11

The guys enter a costume contest with Penny's new boyfriend.

The Big Bang Theory - Season 4 Episode 10

Amy realizes she has feelings for Penny's ex; Koothrappali and Wolowitz try to prove who would be a better superhero.

The Big Bang Theory - Season 4 Episode 9

Penny asks Leonard to lie to her father (Keith Carradine); Howard, Raj and Bernadette pull an all-nighter at a telescope.

The Big Bang Theory - Season 4 Episode 8

While the guys camp out for a long-awaited movie screening, Penny and Bernadette invite Amy to her first slumber party.

The Big Bang Theory - Season 4 Episode 7

Howard baffles Sheldon when he won't accept his apology; and an FBI agent (Eliza Dushku) interviews the guys for Howard's security clearance.

The Big Bang Theory - Season 4 Episode 6

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

The Big Bang Theory - Season 4 Episode 5

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

The Big Bang Theory - Season 4 Episode 4

An embarrassing secret of Wolowitz's is revealed; Raj and Sheldon get into a war at work.

The Big Bang Theory - Season 4 Episode 3

When Sheldon searches for an alternative to human companionship, the guys become concerned.

The Big Bang Theory - Season 4 Episode 2

Realizing he will not live long enough to download his consciousness into a robot body, Sheldon tries to extend his life span.

The Big Bang Theory - Season 4 Episode 1

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

The Big Bang Theory - Season 3 Episode 23

While Penny worries that dating Leonard has ruined her for normal guys, Wolowitz and Koothrappali search for Sheldon's perfect match online.

The Big Bang Theory - Season 3 Episode 22

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

The Big Bang Theory - Season 3 Episode 21

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

The Big Bang Theory - Season 3 Episode 20

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

The Big Bang Theory - Season 3 Episode 19

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

The Big Bang Theory - Season 3 Episode 18

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

The Big Bang Theory - Season 3 Episode 17

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

The Big Bang Theory - Season 3 Episode 16

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

The Big Bang Theory - Season 3 Episode 15

Leonard can only bring one guest on a trip to see CERN's Large Hadron Collider (the world's largest and highest energy particle accelerator) in Switzerland on Valentine's Day.

The Big Bang Theory - Season 3 Episode 14

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

The Big Bang Theory - Season 3 Episode 13

A robbery of their apartment sees Leonard and Sheldon call on their friends to devise a security system.

The Big Bang Theory - Season 3 Episode 12

Leonard is aghast to find out a secret of Penny's: she believes in psychics. Meanwhile, Sheldon tries to assist Koothrappali in picking up a girl at a university party.

The Big Bang Theory - Season 3 Episode 11

Leonard's mother (Christine Baranski) visits, which pleases Sheldon but upsets Leonard. .

The Big Bang Theory - Season 3 Episode 10

Sheldon attempts to help Penny understand Leonard's work, and Wolowitz becomes jealous when Leonard starts hanging out with his new girlfriend.

The Big Bang Theory - Season 3 Episode 9

Barry Kripke embarrasses Sheldon on NPR, and the gang rallies to help him get his revenge. Wolowitz, desperate to keep his romance with Bernadette alive, gets advice from a fantasy version of Katee Sackhoff.

The Big Bang Theory - Season 3 Episode 8

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

The Big Bang Theory - Season 3 Episode 7

A squabble between Leonard and Penny sees Sheldon playing mediator, though out of his own incovenience from the sitiation rather than altruism.

The Big Bang Theory - Season 3 Episode 6

Sheldon teaches Leonard how to understand football while a kite-fighting incident threatens Howard and Raj's friendship

The Big Bang Theory - Season 3 Episode 5

Sheldon seeks revenge on his nemesis, Wil Wheaton; Wolowitz wants Penny to set him up with one of her friends.

The Big Bang Theory - Season 3 Episode 4

Raj must find a new job or be sent back to India, but Sheldon has a solution, which leaves Leonard and Penny dealing with Howard as third wheel.

The Big Bang Theory - Season 3 Episode 3

Howard takes Raj along to check out the Goth dating scene. Sheldon uses chocolate as part of a behavior modification experiment on Penny.

The Big Bang Theory - Season 3 Episode 2

Sheldon and Howard wager comic books over a cricket's species. Meanwhile, a less-than-perfect romantic night agonizes Leonard and Penny.

The Big Bang Theory - Season 3 Episode 1

Sheldon flees back to Texas in disgrace when he learns the guys tampered with his arctic expedition data, forcing the guys to follow him and threatening Leonard's hopes for a romantic encounter with Penny.

The Big Bang Theory - Season 2 Episode 23

Leonard and Penny come to terms with their feelings for each other, as Leonard prepares himself for a three-month long science trip.

The Big Bang Theory - Season 2 Episode 22

Things begin to look up for Leonard when Penny makes a surprising revelation on her second date with Stuart. Meanwhile, Wolowitz enlists his friends' help when he discovers a critical design flaw in his project for NASA....

The Big Bang Theory - Season 2 Episode 21

Leonard and Koothrappali take a heartbroken Wolowitz to Las Vegas, leaving Sheldon locked out of his apartment and forced to bunk with Penny.

The Big Bang Theory - Season 2 Episode 20

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

The Big Bang Theory - Season 2 Episode 19

Penny feels threatened when another sexy woman moves into the apartment building.

The Big Bang Theory - Season 2 Episode 18

Penny's business selling hair products out of her apartment gets out of hand when an over-caffeinated Sheldon takes charge.

The Big Bang Theory - Season 2 Episode 17

The gang is thrilled when they learn Terminator: The Sarah Connor Chronicles' Summer Glau is also aboard their train to San Francisco.

The Big Bang Theory - Season 2 Episode 16

Paintball leads to a squabble between Sheldon and Penny, as well as romance between Howard and Leslie.

The Big Bang Theory - Season 2 Episode 15

Leonard suffers through a dreadful visit from his mother (Christine Baranski) that ends up bringing him and Penny closer.

The Big Bang Theory - Season 2 Episode 14

Sheldon helps Penny with a financial crisis, but his solution leads to a confrontation between Leonard and Penny's burly ex-boyfriend Kurt (Brian Patrick Wade).

The Big Bang Theory - Season 2 Episode 13

Sheldon creates a scientific procedure for making friends.

The Big Bang Theory - Season 2 Episode 12

Penny's criticism of Wolowitz's romantic life pushes him into depression and AWOL for a fighting robot battle the rest of guys are depending on him for.

The Big Bang Theory - Season 2 Episode 11

Penny informs Sheldon that she intends to give gifts to him and Leonard on Christmas which happens to be around the corner. After considerable debate with Penny, Sheldon agrees to also give a gift to Penny on Christmas.

The Big Bang Theory - Season 2 Episode 10

Leonard's relationship with Stephanie is moving too fast for him, so he runs to Penny for advice.

The Big Bang Theory - Season 2 Episode 9

Sheldon is overexuberant that Leonard finally has a girlfriend matching his high standards.

The Big Bang Theory - Season 2 Episode 8

A girl Wolowitz has a major crush on falls for Leonard.

The Big Bang Theory - Season 2 Episode 7

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

The Big Bang Theory - Season 2 Episode 6

Sheldon, and his friends, are mystified when a younger grad student is attracted to him.

The Big Bang Theory - Season 2 Episode 5

An intervention is used to try to force Sheldon to overcome his fear of driving.

The Big Bang Theory - Season 2 Episode 4

Full of confidence following getting a paper published, Raj hits on Penny.

The Big Bang Theory - Season 2 Episode 3

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

The Big Bang Theory - Season 2 Episode 2

Leonard begins dating Sheldon’s nemesis, Leslie Winkle, after seeing Penny with a handsome new guy.

The Big Bang Theory - Season 2 Episode 1

Penny opens up to a reluctant Sheldon after a less-than-stellar first date with Leonard.

The Big Bang Theory - Season 1 Episode 17

Leonard comforts Penny after she breaks up with her boyfriend, again. After asking her out on a date they each turn to Sheldon for advice. Also, Howard teaches Sheldon Mandarin so he can complain about his not-so-tanger...

The Big Bang Theory - Season 1 Episode 16

After finding out Leonard has never had a birthday party Penny decides to throw one for him (and forces Sheldon to join her). Unfortunately things do not go as planned and Wolowitz ends up in the emergency room.

The Big Bang Theory - Season 1 Episode 15

When Sheldon's attractive twin sister Missy comes to visit the guys fight over her. Sheldon ends up trying to be protective of her, much to her displeasure.

The Big Bang Theory - Season 1 Episode 14

Leonard buys a replica time machine online. As the boys move it into the apartment they accidentally make Penny late for work causing her to lash out at Leonard for his nerdy ways. Upset, Leonard decides to get rid of al...

The Big Bang Theory - Season 1 Episode 13

The guys decided to compete in a physics bowl but find Sheldon's showboating too much and kick him off the team. Upset, Sheldon forms his own team to compete against them.

The Big Bang Theory - Season 1 Episode 12

Sheldon and Leonard look for a way to derail a 15-year-old physics prodigy's research.

The Big Bang Theory - Season 1 Episode 11

When Sheldon gets sick, Leonard and the boys know what's in store and avoid him like the plague, leaving an unsuspecting Penny to nurse the world's worst patient back to health.

The Big Bang Theory - Season 1 Episode 10

After hearing Penny sing, Leonard lies to avoid seeing her perform, but Sheldon takes it one step further with a more elaborate lie that leads to the appearance of his non-existent cousin.

The Big Bang Theory - Season 1 Episode 9

When Sheldon and Leonard are invited to present their joint findings at a physics conference, Sheldon refuses. But when Penny steps in to mediate, it only deepens the rift between the two best friends.

The Big Bang Theory - Season 1 Episode 8

Koothrappali's parents want him to go out with another Indian woman with the hopes of initiating a pre-arranged marriage. But his date turns out to have more in common with Sheldon.

The Big Bang Theory - Season 1 Episode 7

When Wolowitz hooks up with Penny's old friend, it ruins "Halo Night" for the rest of the guys.

The Big Bang Theory - Season 1 Episode 6

The guys are invited to Penny's Halloween costume party. During the party, Leonard has a run-in with Penny's ex-boyfriend.

The Big Bang Theory - Season 1 Episode 5

Leonard and his colleague Leslie spend the night together. But Leslie tells Leonard after the fact that she's only interested in a one-night stand.

The Big Bang Theory - Season 1 Episode 4

Sheldon's mother visits to get him out of the funk he's in after he is fired for disrespecting his new boss.

The Big Bang Theory - Season 1 Episode 3

Leonard gets upset when he discovers that Penny is seeing a new guy, so he tries to trick her into going on a "date" with him.

The Big Bang Theory - Season 1 Episode 2

Penny is furious and more than a little freaked out with Leonard and Sheldon when they sneak into her apartment overnight, and clean it while she is sleeping.

The Big Bang Theory - Season 1 Episode 1

A pair of brilliant theoretical physicists meet a woman who shows them how little they know about the real world.