My answer is my Fallout 3 character. Why? Because he eats people, makes people explode in blood, is a slaver, a mercenary, a thief, a whore lover, a desperado, a wildman, and the destroyer of an entire city at one press of a button.
But from the poll I picked Atlas. But only because that's my username on GiantBomb.com. Also because I loved BioShock.