He's one of the toughest ones for me to rank, personally. In some ways, no fighter ever captured the world's imagination more than Mike Tyson. The current main HW champ is named after him. He cultivated an image of ferocity and destruction unlike any hw ever did or probably ever will again. And he was a genuinely awe inspiring hw at his peak. Pound for pound, or at least inch for inch, he would be my pick for the greatest H2H hw of all time. To see a tiny guy (comparatively, and really only about average heighted for a normal man) beat much, much bigger fighters in the way he did was remarkable. For a couple years, he was by far the best fighter of his era. But, Lennox Lewis, who was actually older than Tyson, eventually proved himself the overall better fighter of the larger era. Some would argue Holyfield did as well. That makes it hard for me to elevate him above some other deserving HW's. Plus, the only true ATG he beat was a badly declined and ring rusty Larry Holmes. But, he was champ for well over three years, and had 9 successful title defenses, in the top 10 all time. Between that, and his huge cultural impact as a HW, I'd put him at #12 all time. But top 10 would be very fair.