Regarding the opposite sex, they're on a steep learning curve. In every other sense, they're geniuses. Join physicists Leonard Hofstadter (Johnny Galecki) and Sheldon Cooper (Jim Parsons) as they ponder black holes, chemical deviations, girls, and other mysteries of the universe in all 24 phenomenally funny episode of the Season Five. With Penny (Kaley Cuoco) and Leonard's relationship in uncharted terrain, Sheldon, Howard (Simon Helberg), and Raj (Kunal Nayyar) discover that the feminine mystique is something that cannot be easily graphed or calculated. As they muddle through relationship "bugs" and romance re-launches, they also discover it's nothing a good roll of the D&D dice or a paintball tournament can't solve.
The fifth season of The Big Bang Theory
settles into a solid, enjoyable groove. The original quintet of four nerds and a pretty girl has been complemented by two nerd girls, creating a dynamic social world that retains all the social awkwardness needed for comic effect. Much of the season revolves around relationships: Howard (Simon Helberg) is engaged to Bernadette (Melissa Rauch), though that bond is tested by everything from Howard getting commissioned to be an astronaut to online revelations of Howard's former sleaziness; Leonard (Johnny Galecki) and Penny (Kaley Cuoco) start dating again, this time as "Leonard & Penny 2.0," promising to treat problems as bugs that can be reported and fixed; and Sheldon (Jim Parsons) and Amy (Mayim Bialik) formalize their relationship with--what else?--a contract, though a dissatisfied Amy later decides to make Sheldon a better boyfriend through sneaky behavior modification.
But some of the most delightful bits come from Raj (Kunal Nayyar), the show's remaining singleton, whose ambiguous sexuality flavors everything he says. Nayyar's performance grows increasingly charming, as does Bialik's; in addition to her grappling with Sheldon's impermeable narcissism, the strange undercurrent of lust in Amy's friendship with Penny stirs up comic anxiety. And of course Sheldon never fails to delight as, among other things, he lets all his decisions be determined by a roll of the dice; treats Leonard as "Schrödinger's Friend"; and embraces chaos in his life by playing bongos in the middle of the night and wearing Tuesday pajamas on Thursday night. All in all, though season five feels less surprising than previous seasons, the quality of the writing and performances remains high. The extras on The Big Bang Theory: The Complete Fifth Season are unremarkable, except for a featurette about the series' director and designers, which shows a different side of network television. Guest appearances included the recurring Wil Wheaton, Brent Spiner, Stephen Hawking, and a vocal performance by Leonard Nimoy as Sheldon's conscience. --Bret Fetzer