Show summary:
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.
Sheldon is in seventh heaven and prepared to do whatever it takes to meet his science idol Stephen Hawking, who is working on a project with Wolowitz.
Raj may have found his soul mate after his parents set him up on a date. Meanwhile, Sheldon thinks he's going out of his mind when he begins hearing the voice of Spock (Leonard Nimoy) after he breaks Leonard's "Star T...
Sheldon opts to spend a weekend playing video games with the guys instead of attending a birthday party for Amy's aunt.
After his barber is hospitalized, Sheldon undergoes a hair-raising change in lifestyle as his carefully planned daily routines are thrown for a loop. Meanwhile, Howard is up in the air about continuing his astronaut t...
Sheldon and Kripke square off in a series of sports-related competitions to win a coveted corner office at the university. Meanwhile, Penny feels uncomfortable accepting a gift from Amy.
Sheldon takes it easy by working with Amy at her neurobiology lab after the university orders him to take a vacation. Meanwhile, Howard gets worked up when Bernadette suggests they sign a prenuptial agreement.
The friendship contract is in danger of being nullified when Leonard tires of Sheldon's selfish ways, and Wolowitz is spacing out over selecting an astronaut nickname for himself
Leonard and Penny give dating another try, while Raj begins a rather unorthodox relationship with the virtual assistant on his phone.
Everything might change when Leonard offers Penny a spur of the moment invitation to a romantic dinner for two
Amy is upset with Sheldon when he isn't impressed with her recent accomplishment; Howard struggles with Bernadette's aversion to children.
Leonard confronts his fears when he's contacted by a bully who tormented him in high school
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
Leonard and Penny attempt to hang out alone; and Sheldon tries to overcome his fear of birds
Amy is crushed when Bernadette and Penny go shopping for wedding dresses without her
Leonard feels threatened when a charming comic-book artist comes between him and Priya; and Sheldon is determined to scare his friends on Halloween
Sheldon's mom visits, and he competes for her attention, which seems more focused on his friends.
Leonard and Sheldon attend a party at the home of Sheldon's nemesis, Wil Wheaton (in a cameo along with Brent Spiner).
Raj meets a woman with whom he's able to talk.
Leonard and Amy get to know each other better, while Howard and Bernadette spend the weekend with Mrs. Wolowitz.
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.
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
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 witho...
Howard finally tells his mother that he's marrying Bernadette, and the news puts her in the hospital.
Raj makes an attempt to cure his phobia of talking to women; and Penny spies on Leonard and Priya with the help of Bernadette.
Priya uses her legal expertise to rip apart Sheldon's roommate agreement, and the women take the flustered Sheldon out dancing
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 guys become sleuths to find out who hacked Sheldon's online-game account
Leonard is forced to choose between Penny and his new girlfriend, Priya; Howard's magic trick drives Sheldon crazy.
Sheldon is upset when he realizes Leonard is the center of their group of friends.
Wolowitz considers taking things with Bernadette to the next level; Leonard and Raj's sister rekindle their relationship.
A wealthy donor makes Leonard question what he is willing to do for science.
Sheldon takes acting lessons from Penny in hope of becoming a better teacher; Koothrappali fantasizes about his friend's girlfriend.
Bernadette runs into her ex-boyfriend (Rick Fox) while attending a science event with Wolowitz.
Leonard's idea for a smartphone app derails his friendship with Sheldon.
The guys enter a costume contest with Penny's new boyfriend.
Amy realizes she has feelings for Penny's ex; Koothrappali and Wolowitz try to prove who would be a better superhero.
Penny asks Leonard to lie to her father (Keith Carradine); Howard, Raj and Bernadette pull an all-nighter at a telescope.
While the guys camp out for a long-awaited movie screening, Penny and Bernadette invite Amy to her first slumber party.
Howard baffles Sheldon when he won't accept his apology; and an FBI agent (Eliza Dushku) interviews the guys for Howard's security clearance.
Leonard keeps an affair secret from Sheldon, Howard and Raj.
Leonard realizes he's the only one without a girlfriend, while Sheldon wants to get rid of his.
An embarrassing secret of Wolowitz's is revealed; Raj and Sheldon get into a war at work.
When Sheldon searches for an alternative to human companionship, the guys become concerned.
Realizing he will not live long enough to download his consciousness into a robot body, Sheldon tries to extend his life span.
Penny tags along on Sheldon's first date; Wolowitz finds a new use for a robotic arm.