little info on what Kishimoto said about Sasuke in regards to a question on whether he is "Good" or "bad":
"Sasuke is bassically a vey pure person who doesn't think about whether what he does is 'good' or 'bad', he just does what he wants to do, which causes trouble for others. He's very Self-centered, only concerned with Himself. Some people might think what he does is good, like avenging his parents or trying to realize his brothers Ideals, but he is troubling others with his pursuites, so that aspect is bad. so it's hard to say with clarity, but it's all about whether it's good or bad to be self-centered with your goals. I'd say he's not good or bad, he's just pure." -Masashi Kishimoto
~Kurama