7. Chuck Liddell - Bones, Criminal Minds
Liddell mostly just plays himself in movie and TV roles, so I debated including him, but he's appeared in quite a bit over the years, and that's not counting appearances in advertisements. I rather liked his turn on Bones, where he gets sucker-punched by a dying man who had "hit Chuck Liddell" or the like on his bucket list. The Iceman also appeared on The Simpsons and Entourage as himself, and as an actual character on an episode of Criminal Minds: Suspect Behavior. Liddell has enough charisma to make it as an actor, and I'm frankly surprised that he hasn't found a way into a franchise like The Expendables yet.