Dark side made me upset and it was harder for me to figure out the subplots of my characters when I just killed off whatever it was that was bothering them.
Light Side was enjoyable for the fact that you learned what was going on in people's minds and they weren't so pissed off at you the whole time.
You could just be good the whole way through up until Bastilla. If you want to be evil, just kill her and there is the evil ending.
That actually pissed me off. I felt a little cheated that that was the deciding factor into all of it. I wish the ending was a little more affected.