I support the death penalty but only in the most extreme of cases. I think it is only a suitable punishment in cases of murder and multiple offenses of rape.
A life in jail without parole is usually the way to go, I think. But there are situations, albeit very few, that call for harsher punishment. While the whole "what if they're later proven innocent" thing is a cause for concern, this happens rarely enough that this is most certainly the exception and not the rule, and so isn't even a very legitimate point in opposing the death penalty, I think.
Also -- to those who say that it's not "our place" to choose whether someone lives or dies: what about the victims who died at the murderer's hands? Did they get a choice in whether they lived or died? No. They were killed and they didn't have a say in that. The way I see it, the moment you decide to take another person's life, you forfeit control over your own life. The moment you decide you have the authority to kill a human being, you cease to be a human being yourself, and you've become a menace to society and don't deserve to continue living your life.
And that is why I think the death penalty is acceptable in such cases.