Well technically the two best opponents he beat were Holmes, Spinks. But i always liked his fights vs Razor Ruddock, because Razor Ruddock was a feared Heavyweight at the time. And no one wanted to fight him at that time, and Mike Tyson showed heart and a good chin in both fights.

I know people say he wasn't in his prime in both fights, but i disagree i thought he looked very good in both fights. Especially his bodywork which made me wince just watching it.