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). All in the furtherance of award-winning genius comedy. Languages: English and Portuguese; Subtitles: English SDH (Subtitles for Deaf and Hearing Impaired), French, Portuguese and Spanish, Gag Reel. "Actor on Actor: The Big Bang's Theory of Relativity" Featurette - This fun and light-hearted piece features the stars of the show conducting interviews with each other detailing their experiences working on one of the hottest comedies on television. "The Barenaked Ladies on Big Bang Theory" Featurette - Having created one of the greatest theme songs in recent history, the Barenaked Ladies bring it home when they come to the set of "The Big Bang Theory" to record a music video for the song. Featuring an interview with the band, behind the scenes footage of the filming of an episode, and clips from the new video itself, this piece carries with it all of the fun and energy you could expect from both the band and the show; "The History of Everything" Music Video.