The Big Bang Theory

Outraged that he's being forced to work with his university nemesis, Barry Kripke, Sheldon faces a crisis of conscience. S6, Ep14

When Sheldon and Leonard fight, it affects Penny and Amy's living arrangements. Meanwhile, Raj takes care of Mrs. Wolowitz while Howard is away. S6, Ep15

While the guys try to give their significant others the perfect Valentine's Day, Raj and Stuart throw a lonely people party at the comic book store. S6, Ep16

After a terrible date, Raj vows to never leave his apartment again. Meanwhile, Penny actually impresses Sheldon with her acting skills. S6, Ep17

Contractual Obligation Implementation. Leonard, Sheldon and Howard try to advance the cause of women in science by speaking with junior high girls about their future careers. S6, Ep18

When Howard finds a letter from his father, he's forced to confront his past. And Leonard and Penny throw a grown-up cocktail party at the apartment. S6, Ep19

Let the battle begin! Leonard, Sheldon and Raj fight for tenure at the University - and the competition heats up when the girls get involved! S6, Ep20

After one of his favourite TV shows gets cancelled too soon, Sheldon feels lost, so Amy tries to help him get over his compulsive need for closure. S6, Ep21

Leonard and Sheldon hire Professor Proton, the host of their favourite childhood TV show, to perform. Raj leaves his dog with Howard and Bernadette. S6, Ep22

When the girls' trip to Vegas falls through, the guys invite them to a Dungeons & Dragons date. Meanwhile, Raj and Lucy go on an awkward date. S6, Ep23

When Leonard is offered an exciting new job opportunity overseas, Sheldon grows jealous. Raj pushes Lucy a little too far in their relationship. S6, Ep24