All these guys are pretty good. With Nasser's back he was never going to be the best, but he was a deserving second a couple of times, which is very impressive out of all the bodybuilders in the world!
Flex was great too, but looked pretty small next to Nasser and Ronnie, something he overcame with condition and shape a few times. Neither has ripped asses like Ronnie, or lats from hell like Ronnie. Nasser had the size but inferior back. Flex had the the back in one shot but not in another, and his quads, though ripped, were pretty small next to these guys.
All nit-picking with these awesome legends though!