I'm putting Vitor Belfort in at middleweight, but he's fought all over the map through the years: middleweight, heavyweight, and his most recent fight was at light heavyweight. Despite that, he's the middleweight number one contender, and a scary, scary guy in the ring. Again, here's a guy who doesn't just hit hard, he kicks hard as well. The Pride, Affliction, and UFC vet has 17 wins by TKO or KO over his career, including pure KOs of Luke Rockhold, Dan Henderson, Yoshihiro Akiyama, Matt Lindland, and Kazuo Takahashi. He also holds TKO wins over everyone from Tank Abbott to Wanderlei Silva to Michael Bisping. Take this one to the bank: whatever you think of his personality or ethics, Vitor Belfort is one hell of a hard hitter.