The Big Bang Theory: The Complete Fourth Season

The Fourth Season of The Big Bang Theory finds more hijinks for the science nerds, the introduction of new characters like Raj's sister Priya (Aarti Mann), an expanded role for Mayim Bialik as Sheldon's girlfriend, and guest-appearances by Eliza Dushku, LeVar Burton, and Keith Carradine, as well as the return of Wil Wheaton, Barry Kripke (John Ross Bowie), and Laurie Metcalf as Sheldon's mother.

This season's episodes include Sheldon's (Jim Parsons) pussycat phase, Howard (Simon Helberg) and Bernadette (Melissa Rauch) getting back together, Penny (Kaley Cuoco) and Amy become besties, Sheldon is baffled by Howard's magic trick, an attempt to create an iPhone app, Leonard begins a relationship with Raj's (Kunal Nayyar) sister, Sheldon attempts to throw a party with a new group of friends and takes part in a girls night out, the gang takes part in a New Year's Eve costume contest, and Leonard meets Penny's father.

In one episode the guys go see Raiders of the Lost Ark on the big screen (only to be thwarted by Sheldon's arch-nemesis) while the girls have a slumber party, and in the season's best episode a weekend getaway turns into a crazy bed-hopping night and an angry morning. And, in the season finale, a drunken night leads to some serious ramifications for next season.

Extras on the three-disc set include an interview with the Barenaked Ladies discussing the show's theme song, a gag reel, a music video for the theme song, and the actors pairing off to interview each other on their experiences working the show.

This is an easy recommendation for fans of the show, especially if you can find a set with the free t-shirt for Mystic Warlords of Ka'a (the fictional trading card game played over the course of the series).