The problem with The Big Bang Theory is that it pretty much consists of five jokes, one per main character. It tries to do the whole thing with extra jokes which are hidden and only nerds will get, but wrecks it with factual mistakes (even as early as the first episode with Sheldon's misuse of the term "Parallax Distortion") and the fact that Futurama's been doing the same thing better, for longer. In general, the writers are attempting to write characters smarter than they themselves are, and the writing suffers for it.
It's weird, because Two and a Half Men is written in pretty much the same style, but it pulls it off because it's SUPPOSED to be extremely low-brow, and as such isn't constantly shooting itself in the foot. Not to mention, an insult in the form of a pun is funnier than an insult in the form of big words and "ooh isn't Sheldon so smart".