I can’t resist mentioning a joke I heard from an episode of American Dad. Stan Smith has this to say about his training as a negotiator:
Hey, you’ve got one of the CIA’s top negotiators on your side. Y’know, I negotiated my way through negotiator training. I should’ve failed the hell out of that class. That’s how good I am.
It reminds me of some of the issues that cropped up in Scott Aaronson’s discussion of side-splitting proofs, especially Theorem 5. I can’t help but chuckle at the fact that Stan’s line gives both a lower and an upper bound on the quality of his negotiation skills!
Anyone know of other jokes like this one?
Annoying Precision 
There’s of course the classic Groucho(?) diagonalization joke “I wouldn’t want to belong to any club that would have me as a member.”
I suspect Futurama has some, but the closest I can think of now is “Your lyrics lack subtlety! You can’t have your characters simply announce how they feel! That makes me feel angry!”