"Four seasons in, it is still laugh-out-loud funny. Every episode, every week," USA Today's Robert Bianco says about the hit series The Big Bang Theory. Here's your chance to subject his conclusion to empirical analysis by watching all 24 Season 4 Episodes! This season the Big Bang gang's romantic universe expands. On the rebound from Penny, Leonard falls into the arms of Raj's sister Priya. Sheldon gets a girlfriend, or rather a friend who is a girl: Amy, a dour neurobiologist who declares herself besties with Penny. Howard and Bernadette heat up. And so do Raj and Bernadette (at least in Raj's Bollywood daydream). Observe all the forces of attraction in this genius, award-winning comedy.
- Blu-ray Exclusive: "The Big Bang Theory Live!" - Experience the Excitement of a Live Show Taping
- "Actor on Actor: The Big Bang's Theory of Relativity" - Cast members interview each other about favorite season moments
- Barenaked Ladies Series Theme Song Music Video
- Gag Reel