Mike Tyson most likely.
But on the other hand being huge like Ben Affleck instead of having killer boxing skills sounds like more of a sweet deal to me... 
hey bruce, back int he day i was a super hardcore boxing fan, and tyson was my favorite fighter bar none,
tyson was his most cut during his first three comeback fights after prison, i honestly beleive he was focused at that time, after he beat frank bruno , i think he got into partying, and never looked as cut or in shape for any of his fights after that.
here is a pic of him when he fought peter mcneely this was the leanest ive seen tyson look