While in WoW, I play Horde because the races are so much cooler and who doesn't want to contradict your origins as a undead priest, being a anti-holy being using holy powers, while the Sith is cool, I prefer to be Jedi, and will be a Knight (or Consular, still not 100% sure) when I eventually get the game after the price has gone down and some launch things fixed over.
While in single player games I can be a dick sometimes, I feel like personally, NOT being the Jedi I always wanted to be in real life is just lying to myself...that and I couldn't be a Sith, cause if I get attached to someone, I can't screw them over. I'd never be a master Sith cause I'd get attached to my mentor and never try to take their place Dictator style by making them proud and killing them. They'd call me weak, I call me, a Jedi