I have to give props to the guy who mentioned Nicolas Cage. I voted for Stallone, and I stand by that, but Nicolas Cage is actually my favorite actor PERIOD, and he is a great action star as well. Cage is a guy who has a lot of good movies that have flown under the radar, but that should be more highly revered. I love Nicolas Cage, he is the man, and that is that.
Stallone takes the cake for me on this one. Now I don't know that you'd count them as "Action" flicks but the Rocky franchise is a major feather in his cap and it's hard to vote against Rocky Balboa in any contest.
Not to be forgotten, the Rambo movies are not just great action flicks but good movies in general, especially the first one.
Another great action flick that I think tends to go unnoticed from Stallone that just kicks major ass is none other than Cobra. Yeah, that's right baby, Cobra! Stallone as Marion Cobretti was fucking epic. He was a complete bad ass on par with any other action movie bad ass you'd care to mention.
You can never forget Demolition Man either. Another great action movie from Stallone, and it didn't hurt that he was working alongside Wesley Snipes, Sandra Bullock, and Dennis Leary. This is one of my favorite future based movies and an action flick for the ages that speaks to Stallone's position at the top of the action star rankings.
Cliffhanger, Cop Land, Get Carter, Over The Top, Lock Up, Tango and Cash, The Specialist, Judge Dread, Death Race 2000, F.I.S.T, Nighthawks, etc.... This guy has the resume. The other thing is, Stallone is still going and kicking ass as we've seen in the last few years with "Rocky Balboa", "Rambo", "The Expendables" and he has other movies about to come out and yet to be filmed, so at the least you've got to say he's also shown the staying power few others can even touch.
I don't discount Arnold by any means. If Stallone is #1 in my book, Arnold is #1A and I would be very torn to have to actually choose one over the other as I love both of them and they've both made a lot of great action flicks.