The Clown Prince of Crime
Super Freak
Arnie had a good run of about 12 years from Conan-True Lies when he was pretty much cinema gold. Every project he touched seemed to turn out great. As you said there was the odd turkey but every 2nd or 3rd movie was a hit. Maybe they were more movies or their time and Arnie was in the right place at the right time. To get the right roles.
Like everyone though, Arnie has a shelf life. I would rather see a young muscle bound Arnie kicking ass in Commando, then some old due mumbling the same old lines , that we have heard a million times before.
Part of Arnold's appeal as an action star, besides his cheesy one-liners, charm and charisma, was his massive body. Once his body started to go, there was only so much he could do with just charisma, and he no longer looked like a real life action figure. Luckily, as the Terminator he can now look old and still be a "superhero" because he's a machine. However, outside of that role, he doesn't have anything else anymore. Stallone saw the value of having a large physique, and he enhanced himself and arguably achieved more box office success in the 80's than Arnold, but his appeal was never just his body, it was his acting and underdog gimmick, even when playing action characters. That's why he can still go back to the Rocky/Rambo well and get away with it.
I wonder how long will The Rock be able to maintain his physique as he gets older.