I can't argue with any of those. I can't narrow it down to four...I want Larry Scott since he was the first Mr. Olympia. Lee Haney won a ton, but the 80's were kind of a down period to me. Arnold and Ronnie are no-brainers. And Dorian took bodybuilding to a new level.
"Everybody wants to be a bodybuilder, but don't nobody wanna lift no heavy-ass weight!"