Light Side. Sith are more badass, but they are always fucked over either by themselves or an apprentice. It sucks knowing that you killed your boss to get where you are and that everyone under you wants to kill you, or will try, even if you're strong enough to kill them. Eventually you will grow weak, and the instant that happens you're as good as dead. Plus, most Sith come back to the lightside eventually anyways so cut out the middle man... OH I JUST KILLED MILLIONS OF PEOPLE BUT NOW I AM CHANGING SIDES... seriously that always pissed me off, someone who is that far gone in evil won't turn back for something so stupid as emotion... they would have NO EMOTIONS.