Gonna go with Doomguy here. He's brought the armies of hell to their knees on more than one occasion. Also, unlike those Warhammer guys, Doomguy doesn't need tanky armor or (presumably) genetic modifications. He can kick the hell out shit just the way he is.
Plus he can punch people into a fine red paste. Never argue against a guy that can do that.
Plus he can punch people into a fine red paste. Never argue against a guy that can do that.