OK, puns are funny and don't poke fun an anyone. But most jokes do, yet many of them are funny and in poor taste/offensive.

I still don't find most terrorism jokes funny, but that doesn't mean I think nobody should be allowed to tell them. People who know me don't tell them to me, and that's enough.

By the same token, keep your sexist and racist jokes out of the office, but not necessarily out of your lives, if they are funny, the jokes I mean, not your lives.

Why don't women have brains? Because they don't have a penis to carry'm around in! is a funny joke you can't tell at the office, even though it is funny. Yes it's sexist, but it's still funny.