I believe Michael Jai White is the most underrated Martial Artist/Actor in the business. Constantly wanting to discuss my favorite Martial Artist/Actor, I find most people don't even know who he is. He's the guy that put a beating to Jean Claude in Universal Soldier 2. Undisputed 2 allowed him to display his skills as a matial artist as well. His filiming debut was a HBO movie "Tyson", where he played Mike Tyson. He also played in Silver Hawk. Not really one of my favorite movies, but it still displays his skills. Mostly as a martial artist rather than an actor in this one.