I never liked ctrl+alt+del. It's just... not funny. The fact that it can be kind of offensive doesn't bother me. The just just aren't funny.

xkcd definitely wins (www.xkcd.com). Then again, xkcd is written by a physics grad student, I'm a physics grad student, and the humor in it has a lot to do with more abstract ideas within physics, so I might be a little bit biased on that one...