Bruce Lee: Enter the Dragon; easily his best. The Way of the Dragon (aka "Return of the Dragon) also had its points for being a bit more humorous.
Bolo Yeung: Bloodsport, of course. Even though he only had four lines "Very good, but brick not hit back," "You are next," "You break my record, now I break you, like I break your friend," and "Mate," he did a very entertaining job of playing the part of the bad guy, even if it were a bit overdone. Other than that, I enjoyed him best in "Enter the Dragon," since he was a cold-blooded killer that served the whims of Mr. Han, and was quite effective at doing so. That facial expression with the maniacal smile he had when crushing the failed guard in his arms like a nutcracker, still makes me smile to this date.
Jet Li: Fist of Legend. Dare I say, that I enjoyed it as much as I did with Bruce Lee's "Fist of Fury?" (improperly titled "The Chinese Connection" in the US)
Chuck Norris: As a bad guy, the Way of the Dragon. Cool headed, while able to kick some serious butt. As a good guy, Invasion USA! Yes, yes, I know it's a silly flick, but at the same time, it does have its humorous moments, along with my favorite quote in any martial arts movie: "I'm going to hit you with so many lefts, you'll be begging me for a right."
Phillip Rhee: Best of the Best. Forget the (horrible) sequels. At least the first one had some decent action, and that there was an actual purpose. Also, there was a bit of humor interjected in this one. One of my favorites, despite the presence of Eric Roberts in the film.
Jean Claude Van Damme: The Quest. Better fight scenes than Bloodsport, showcasing a few more martial arts systems as well. Still, I often times wonder what kind of martial arts that African guy was practicing; all I saw was him delivering a clothesline to his opponent, and then getting the snot beaten out of him.
Jackie Chan: Enter the Dragon. No, really. He was the guard at the opium processing factory of Han's who got grabbed by Bruce, and then got his neck violently broken, while Bruce shows an evil smile. I just don't like his types of movies, with the exception of Rush Hour.
Russell Wong: Romeo Must Die. A shame that he hasn't had too much success in America; he's a living legend overseas. Other than this flick, his only claim to fame was in the series "Vanishing Son," that many folks nickname "The Kung Fugitive."