I'd have to say both Bruno fights. In the first fight, Tyson got hurt rocked by Bruno, then he systematically broke Bruno down. Bruno never even fell, but was simply taking powerful shots on the ropes.

In the second Bruno fight, after the ref stopped the fight, Tyson was celebrating. He was genuinely celebrating winning the WBC belt. A surreal and poignant moment in seeing Tyson sincerely happy on live television.