Man, I've got the lamest sense of humor that I just can't express on GTP, not because it violates the AUP on sexual levels, but just because it would all be considered useless spam or clutter on a forum. Stuff like "your face" or "well your mom is my mom" and "you are my mom!" make me laugh, on really basic levels. All of the kiddie alpha-boy stuff, like my daddy can beat up your daddy are the sort of insults I use. They are inoffensive enough to use on a regular basis in regular conversations, but useless enough to not post on GTP. Sometimes I've come so close to using them though.