Venture Bros - best animated series. It's absolutely hilarious. Between the references to geek culture, and the characters themselves, it's just a fantastic show. There's even an episode where the opening dialogue is David Bowie lyrics ad verbatim. "I think...my space ship knows which way to go." "Ground Control to Major Tom, can you hear me Major Tom! Can you hear me!!!"
Although there may already be a thread about this, I have to agree with you, the Venture Bros. is probably the best cartoon ever. With a basis around super science and constant references to Hanna Barbera cartoons, it remains constantly funny, and it finds ways to attract all kinds of fans. If you haven't watched it yet, I highly recommend this show to pretty much anyone, since I don't think there's a single person in the entire world who will hate it.
Also: Brock Samson is my hero.