Saren because, ultimately, his heart was in the right place. He just went about it the wrong way and ended up being manipulated to the point where his original intentions had been blinded by the indoctrination and destruction at the hands of that indoctrination. And then he shoots himself in the head, which was quite poignant, in my opinion, because at that point, he refused to be used as a weapon anymore. He sacrificed himself, and that makes him a much better person in my books.