Melissa Rauch

A new success for Leonard makes Sheldon very jealous and throws Penny for a loop. Meanwhile, Koothrappali pushes Lucy too far in their relationship. (TV-PG L) Also available on Amazon Instant Video and VUDU

When the girls' trip to Vegas falls through, the guys invite them to play Dungeons & Dragons, causing Sheldon and Amy's relationship to take an unexpected turn. Meanwhile, Koothrappali and Lucy go on a very awkward date. (TV-PG D, L) Also available on Amazon Instant Video and VUDU

Sheldon and Leonard hire Professor Proton, the host of their favorite childhood TV show, to perform. Also, Howard and Bernadette run into trouble babysitting Raj's dog. Bob Newhart guest stars as Professor Proton. (TV-PG L) Also available on Amazon Instant Video and VUDU

Sheldon feels lost after one of his favorite TV shows gets canceled too soon and Amy tries to help him get over his compulsive need for closure. Meanwhile, Raj discovers a secret about his new love interest. (TV-PG D, L) Also available on Amazon Instant Video and VUDU

Let the battle begin! Leonard, Sheldon and Raj fight for tenure at the University – and the competition heats up when the girls get involved! Also available on Amazon Instant Video and VUDU

When Howard finds a letter from his father, he's forced to confront his past, struggling with whether or not he should open it. And Leonard and Penny throw a "grown-up" cocktail party at the apartment. Also available on Amazon Instant Video and VUDU

Back to school! Leonard, Sheldon and Howard try to advance the cause of women in science by speaking with junior high girls about their future careers, while Raj plans his date with Lucy (guest star KATE MICUCCI). Also available on Amazon Instant Video and VUDU

After a terrible date, Raj vows to never leave his apartment again. Meanwhile, Penny actually impresses Sheldon with her acting skills. Also available on Amazon Instant Video and VUDU

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. Also available on Amazon Instant Video and VUDU

A fight between Leonard and Sheldon drives Leonard to finally move in with Penny – not realizing how the shift will affect Penny and Amy's living arrangements. Meanwhile, Raj takes care of Mrs. Wolowitz while Howard is away. Also available on Amazon Instant Video and VUDU

Outraged that he's being forced to work with his university nemesis, Barry Kripke (guest star JOHN ROSS BOWIE), Sheldon faces a crisis of conscience. Meanwhile, Howard and Raj spend a thousand dollars on action figures of themselves. Also available on Amazon Instant Video and VUDU

While the guys take a road trip to a comic book convention in Bakersfield dressed as characters from Star Trek: The Next Generation, Leonard's car is stolen. Meanwhile, the girls stay home and try to appreciate the world of comics. Also available on Amazon Instant Video and VUDU