I voted that he was good, but only up until a certain point. He had this tendency to punish petty thieves the same way he punished rapists: Instant Death, no appeals. That's not good. That's pretty solidly gray. I personally would like to think that, if I were to get a Death Note, I would use it only in A) the direst of circumstances and B) only against people who are threatening others with death or severe injury. And, y'know, wouldn't give anyone any hints as to who was doing it. Like putting a giant "L" on a screen and saying "Hey guys, I'm killing criminals!"
Dur.
Of course, as His Ultraness pointed out, the point of the anime is that absolute power corrupts absolutely. So I have no idea if I could do that.