I've played Rifts occasionally since it came out, and prior to that I played TMNT and Heroes Unlimited in the '80's. As far as roleplaying overall goes, I've spent the most time actually playing AD&D, D&D 3 & 3.5, Shadowrun 2 & 3, and Earthdawn 1, but have read and played many others off and on.
In general, I tend to play nonhuman, physically large characters with some unusual abilities and knowledge (racial, superpowers, magic, cybernetics, etc), useful in combat, but preferring noncombat interactions (I hate spending entire sessions working out a single combat!) I'm a big fan of both flight and shapeshifting abilities.
Evil PC's are a major pet peeve. I play HEROES.