Heh.. I've used some of these, especially to Ninja someone.. Here's a few from my groups:
ATM: All Terrain Monk. Used to describe a character that had sufficient magical support to have every movement type, i.e. Wings of Flying, Boots of the North, Pearl of the Sirens, etc...
Crowbar: Term used by above character to describe any weapon, usually a sword, capable of being used to open stuck doors.
Pimpslap or b*tch slap: When someone, usually the BBEG, takes someone else, usually a PC, down in one hit, i.e. "That demon just pimpslapped the hell out of you!"
butch b*tch: Term for a female character played by a male player as a male character.
Lucky Richard: A player of ours was very unlucky in Palladium games when attempting to dodge shots, swings, etc. Therefore he then decided to have his character dodge into the blasts and managed to live. Now used to describe any action that even though is totally suicidal, the character still manages to survive.