My favorite of all time was Paul "Mr. Wonderful" Orndorf. I love the way he would totally freak out in the ring.
Roddy Piper would be a close second, when he was a bad guy though.
Pedro Morales- Morales was the first man in wrestling history to win all three major men's titles in the World Wrestling Federation: the WWWF Heavyweight Championship, the Intercontinental Championship and the WWF World Tag Team Championship