Trying to decide if I play good characters in games with a choice because I am a goody two shoes, or because otherwise I would miss out on a ton of rewards and interesting quests. Unfortunately many of the games screw you out of extra XP, money, items, rewards if you play it through as evil, which certainly influences me when I play a game the first time. Since I am not sure I'll play it soon again, I want to see -everything- of it in the first play through. With KotoR I was ok with doing a second, evil play through, but even then I couldn't get myself to do the "thuggish" stuff. Just did run too contrary to me. Still chuckle about making slavers jump off the station on Nar shaddaa, then taking over their operations though.
On the other hand I enjoy playing bastards in chat/IRC/Forums rpgs. Go figure.