Maybe Joe Louis? Schmeling Baer Braddock Carnera Walcott Charles Marciano Sharkey Plus Lhvy Champs. Conn Lewis
Holyfield faced the most: 1. Pinklon Thomas 2. Michael Dokes 3. James Buster Douglas 4. George Foreman 5. Larry Holmes 6. Riddick Bowe 7. Michael Moorer 8. Mike Tyson 9. Lennox Lewis 10. John Ruiz 11. Hasim Rahman 12. Chris Byrd 13. Sultan Ibragimov 14. Nikolay Valuev This is not counting several other Organizations besides the IBF, WBA, WBC & WBO.
Tire between Lewis and Holmes I think Lewis: Evander Holyfield Mike Tyson Hasim Rahman Oliver McCall Vitali Klitschko Tony Tucker Frank Bruno Ray Mercer Henry Akinwande Tommy Morrison Shannon Briggs Mike Weaver Holmes: Muhammad Ali Ken Norton Mike Tyson Evander Holyfield Mike Weaver James Smith Oliver McCall Ray Mercer Michael Spinks Tim Witherspoon Leon Spinks Trevor Berbick 12 each
Big George has a v.good list - Kenny Norton [robbed in Ali 3] Joey Frazier Shan Briggs Tommy Morrison Evander Holyfeild Jimmy Young [robbed VS Ali] Muhammad Ali Ronny Lyle [robbed VS Ali - B$ TKO] That 8 :smoke
Ali did not do too bad (despite 3 years out and plenty of Return matches) Liston Patterson Terrell Frazier Ellis Norton Foreman Spinks Holmes Berbick
Tyson has 14 (15 if you count Douglas) 1. Ratlif 2. Berbick 3. Smith 4. Thomas 5. Tucker 6. Holmes 7. Tubbs 8. Spinks 9. Bruno 10.*Douglas* 11. Seldon 12. Holyfield 13. Botha 14. Norris 15. Lewis Edit: My bad, 2 Cruiserweights. Only 13 including Buster.
let me try and answer this without seeing the later answer. I think Evander Holyfield. He fought everyone. Dokes Foreman Holmes Tyson Douglas Moorer Lewis Mercer etc etc etc... There are more, but how can there be anyone else.