Big Bang Theory is a wet-your-pants funny show, especially if you're into geek culture. Expect episodes to contain several clever references or shout-outs to video games, comic books, famous scientists, authors, and more. Even if you're not a veteran of all that is nerdy, the show often lets its viewers in on the more obscure references, usually in the form of the main characters explaining something to a non-geek.
The show follows three young scientists (and their blond neighbor), detailing their struggles in their social, romantic, and professional lives. All of the characters are very distinct, and you'll quickly find yourself loving (or loving to hate) each one of them.
The writing is snappy and the punchlines are well-timed. It tends to avoid lowbrow humor, though that doesn't mean the naughtier subjects are never tackled. I was hooked after just one episode, and frankly, if you don't find this series funny then you must have something in common with Sheldon Cooper (the antagonist of the show).