I voted Fedor because he's just so well-rounded. He out- struck Cro Cop and Sylvia, out-jiu jitsu'd Big Nog, beat roided out wrestling monsters like Coleman and Randleman, etc.
My only complaint was going to be that he doesn't finish enough of his fights. However, I ran the numbers and he's actually finished a greater percentage of his wins (79%) than any of the other fighters on that list, including Anderson Silva (which surprised me).