When I first saw the subject title, I was about to say the 'blood eagle'. 
Given the death penalty has become relatively more humane over the years and decades, I would say life in prison, especially American prisons. If you're not already naturally big and strong enough to defend yourself to avoid becoming someone's unwilling 'wife', you're in for a rough time. It really depends on which prison you go to and how old you are. Regular men going to regular men prison don't get raped as much as media suggests it does. Juviniles getting put in with adults do, juviniles get raped a lot in juvenile prisons too. You might not want to go to jail for hurting kids either.
So, don't be a kid and don't hurt kids, and you'll probably not get raped in prison.
