Flex peaked in 1993.
He was always trying to re-attain the 1993 conditioning. However, he was good at the 1996 Arnold Classic.
But the Ninja Attack Bullshit & Synthol usage showed us that he could not find a way to get back to his 1993 condition.
IMO, Dorian's best year was 1993 too. You can argue for 1995, but by then, he had one torn biceps, so I'd go with 1993.
I'd also have to agree on Flex. Imagine that - two of the best bodybuilders ever, and they both essentially peaked almost at the start of their pro careers. If I'm not mistaken, 1993 was Flex's first full year as a pro - so yeah, that's early to be at your very best.
Not that he looked bad later, but he never reproduced that 1993 magic. Sort of like Samir Bannout's 1983 Mr. Olympia performance.