I always cheer for the good guys, so I'd have to say Jedi. Whenever I play video games, I tend to play as a good guy. I'd like to think I'd be a good guy if I was strong in the Force as well.
Besides, the dark side of the force will fork up your face big time. Your face would be so messed up, people would be able to tell you're a Sith from a mile away, and there'd be no way for you to blend in with society and live a relatively normal life, or even have friends. And don't go "Sith can have Sith friends, trololo", because if there's one thing I learned from Knights of the Old Republic, it's that Sith always turn against each other if they benefit from doing so.
