Geek chic has become the style du jour (channelling Wolowitz, meshugana. You knows it.) and BBT is all about the chic geekery. Season 1 was largely spent cementing the main characters personalities and lifestyles and making believable the fact that a "normal" chick like Penny would really become friends with 4 geeks. And not 4 pseudo-geeks. There's Sheldon (played magnificently by Jim Parsons) - the exacting, egotistical, Vulcan-like theoretical physicist; Wolowitz - the tiny Jewish sex-pest (and the unheralded gem of the show); Koothrappali - the Indian physicist with selective mutism and a penchant for yoot lingo and, finally, Leonard - the show's "everyman": the bridge between the normality of Penny and the otherwordliness of the geeks.
Season 2 takes their characters and runs with them. Sheldon becomes even more monstrous and Sheldonesque (they introduce his laugh. His laugh is a breathy machine-gun pant and it's truly a beautiful, beautiful thing), they give us Sheldon in dungarees (dungarees!) and the relationship between Leonard and Penny develops, stalls, develops, stalls... and in a way that isn't remotely clunky or ham-fisted.
In fact, that describes the entire show. Chuck Lorre and Bill Prady must be bonafide geniuses - they dip their toes in things that are notoriously incomprehensible. They dabble in particle physics and rocket science and string theory with consummate comfort and ease. By the same token, the show is drenched in internet memes - it's absolutely up to date and on the crest of the wave. It's not slightly behind the times trying to appear cool: it's genuinely, so cutting-edge-it-bleeds cool. Plus, season 2 introduces Rock-Paper-Scissors... Lizard-Spock*. Genius!
Most of the series takes place in Sheldon and Leonard's flat, as in season 1. The Cheesecake Factory has disappeared, and we are introduced to the comic book store, along with its manager, Stuart. He is a comic book geek cum artist who puts a crimp in Leonard and Penny's possible relationship. In the comic book store - and prior to BBT, I had no idea comics and comic books were different things! - there's a silent character called Captain Sweatpants who hangs around in the background, and, even without dialogue, he's one of the better people on tv right now. That speaks volumes about the awesomeness of BBT's cast, and the writer's talent in creating characters.
This review has become far too long so, suffice it to say, Big Bang Theory is one of the most affectionate, funniest, warmest and cleverest comedies in a very long time.
Season 1 was wonderful; season 2's 23 episodes actually surpass it and, thankfully, 2 more seasons are already assured.
* In case you want to play: Scissors cuts Paper covers Rock crushes Lizard poisons Spock smashes Scissors decapitates Lizard eats Paper disproves Spock vaporizes Rock crushes Scissors.