None of his successors can touch Connery as Bond. I had read all the books when the Bond movies started coming out, and he was exactly what I had imagined Bond to be while reading the books. Even the hair was perfect (of course, it was a wig)
Are we talking true action packed hero? or are we talking overall film badass?
For pure action, I have to vote Jacki Chan. What is he, like 60 now, and he's still doing his own stunts after what, about 100 flicks; falling, jumping, flipping, and climbing like a monkey. For modern action star Tony Jaa is pretty incredible but it remains to be seen if he's going to have a lasting future outside made for Thai audience films.
For overall film badass, it's a tough choice. Clint has a mystique that is hard to replicate, Bruce Li was an actual badass that could literally kick the **** out of, well, anyone, and Arnold's films have some serious action and an extreme box office record.
I would go with Clint. Josey Wales, Dirty Harry, Man with No Name and Filo Beddoe are pretty action intensive just not of the big budget special effect sort.
I never see Harrison Ford as all that believable, but he does make entertaining action movies.
There are different genres, and different types of stars, gotta love Sean Connery as James Bond-he's the perfect Bond.
Predator is great with Arnold taking a mud bath and fighting mano a mano, but there's only one who clearly stands above the rest-Bruce Lee. Incredible martial arts fighter, and he killed Chuck Norris after yanking half his chest hair out and tap dancing on his face.