It would be better to judge each Mr.O's edition. Thinking that there's only been 11 Mr.Os in 43 years just shows how biased is this show.
Franco and Dickerson were the worse by far, then '80 Arnold was a disgrace also. Haney in '89 and '90 was undeserving. Yates in '97 was not great either, Cutler in '07 and so on and so on...
Most impressive wins:
-Probably Coleman in '98 (and '99 was almost as good)
-Yates in '92 and '93
-Bannout: just showed up great that year
-Haney's 83-85
-Zane deserved all his Sandows, except maybe the '79 edition.
And Oliva just have never lost to Arnold.