Which fight were these top heavies peak?

Very good picks. Frazier-Quarry is the one I'd argue with since I think Frazier was still developing (only 24).

I also think Terrell was Ali's pinnacle. He was at his peak and really had something he wanted to show in that fight, not in the best way but stil.

Tyson had a similar mindset against Biggs and was absolutely ruthless in that one, so I can see the argument for it even though I'd go with Spinks myself.