My jokes are so subtle that only one girl in my group understands them, the rest get it after a while and if it was a perverted joke they'd be shocked. Since I'm somewhat Stoic [http://tvtropes.org/pmwiki/pmwiki.php/Main/TheStoic] it shocks them when I pull a funny one.
I have this friend who always says jokes, but she always tells them wrong/mixed up and she goes "aww forget it. It was a joke about [subject]" which is funny in itself because she says it so much.