The asshole can stretch pretty far so I'd say a head

Dexter. Everything

I would like to try Dexter's way just once on somebody. That feeling of empowerment to take someones life. I would probably kill violent criminals, evil politicians. I would like to put all of the Westboro Baptist Church followers in their church and gas them and while.they're slowly suffocating, ill blow up the building then piss on there corpses afterwards.