What's worse: an all-powerful hero, or an all-powerful villain?

Sometimes, a hero becomes so powerful, nothing can touch him or her. Take pre-Crisis Superman, who juggled planets and laughed off nukes. And sometimes, a villain is so unstoppable, your best defense is as much use as a cardboard box. Like the Borg. Or the Observers, who are an army of teleporting super-intelligent telepaths who can catch bullets and do kung-fu.

But which is worse: a hero who's too powerful, or a villain who's too powerful? You decide!