I've done horrible things in my life which I regret every night I lie asleep thinking about them. But I have never wished death upon another person.
Unless you count terrorists such as Bin Laden and dictators such as Jong-Il. I've also never had thoughts of blowing up my school or anything crazy like that, though I got expelled from public school in 3rd grade for shooting my mouth off about it (hardly knew what I was talking about). I've had a harder life than most, and I try my best to make others less miserable.
I don't like to admit it, but deep down I may be depressed.