I always felt that one of the spoils of victory for Bowe when he KO'ed Gonzalez should have been shaving the back of his head. I think that haircut was part of why I disliked him. But mostly it was because he was a twat.
Well, Duran played the part of the heel a fair few times. Though they never fought, he was taking that role in the Arguello rivalry and saying the stuff he did after the Lampkin fight gave him a heel persona. He still managed to be popular though despite that. When you're as good as he was, people will like you regardless. Tyson could say all kinds of outrageous stuff and people would be fasinated rather than repulsed. I don't think Tyson was necessarily liked during his prime, but everyone was in awe of him.
With EUBANK you didn't know how to take him. He said he wanted to maim Watson, then he did and said he was sorry. He used to put on these airs and graces with Nigel Benn like he was some sort of poncey schoolboy who found the village bully too crude. Then he would tell anyone who'd listen that boxing was a mugs game and then he'd preen after stopping some Brazilian stiff.
McClellan didn't really have the longevity but could have been a great heel. With his dog fighting and stories of tying a dogs mouth shut and letting a dog kill it and just his general demeanor. Although you understood McClellan was a genuine gangster type of guy that you wouldn't want to cross. Guys like Hamed, Mayorga, even Tyson to an extent were playing up their character a bit even though they enjoyed hurting guys but McClellan just felt like a purer psychopath than most.