That's is my favorite atheist joke. To be fair, I can't think of another atheist joke offhand, but of the few that I have heard, that is my favorite. Here is my favorite agnostic joke (yes, it also happens to be the only agnostic joke I know): Q: What does an agnostic, dyslexic, insomniac do at night? A: Sits up and wonders whether there is really a dog.