My Rankings:
1. Keanu Reeves. Not a joke. He starred in two of the best action trilogies of all time with some of the best fight choreography. You just can't beat the Matrix or John Wick.
2. Harrison Ford. Indiana Jones, Star Wars, Blade Runner. Enough said.
3. Tom Cruise. He might be insane. He might barely be 5 ft tall. But he's an all-timer. Mission Impossible, Top Gun, Minority Report, War of the Worlds, Edge of Tomorrow. The guy knows how to deliver an entertaining product.
4. Denzel Washington. He doesn't necessarily spring to mind as an "action star" because he is such a great dramatic actor, but he's been in so many solid action movies: American Gangster, Training Day, Book of Eli, Man on Fire, Magnificent 7.
5. Clint Eastwood. Living legend.