1. Archie Moore. To me Archie Moore is the greatest fighter as far as getting better with age and the greatest light heavyweight Champ in history. He had to wait until his 160th professional fight to get his first title shot vs Maxim at age 39 and kept that title until62 when he was about 48 years old. He also gave heavyweight Champ Marciano a tough challenge too. His record after age 40 is 44-4-2.
2. Bernard Hopkins. Bernard is a multi division title winner and certainly a shining example of what a fighter can do when he is dedicated to his craft! And he is simply beating much younger fighters and defying age along the way. Certainly a fighter that is headed for the Hall of Fame and the holder of being the oldest fighter at ag 48 to win a major Championsip.
3. George Foreman. Foreman had 2 careers basically one being the young strong power punching surly fighter not known as being friendly and the older much heavier smiling fighter that everybody loved. Foreman came back after almost 10 years in 1987 at age 38 and willing to fight Mike Tyson! He did the impossible at age 45 by becoming the oldest man to win the heavyweight Championship by knocking out Michael Moore at age 45!
4. Bob Fitzsimmons. First man to hold the middleweight, light heavyweight and heavyweight titles. At age 40 beat George Gardner for the light heavyweight Champonship. Fought until he was 50 years old!
5. Jersey Joe Walcott. Once held the record for winning the heavyweight Championship at age 37 when he defeated Ezzard Charles by shocking 7th round kayo. He certainly seemed to get better the older he got.
6. Evander Holyfield. Last check I had he is still fighting and in 2011 beat a fighter named Brain Nielson who had a 64-2 record by knockout in the 10th round. was robbed vs Valeuv and done quite well past age 40. Only 5 time heavyweight Champ.
7. Larry Holmes. Was 52 wehen he retired and won over 20 fights past the age of 40 retiring after a 39 ear career with only 6 losses.
8. Roberto Duran. He was 50 when he hung up the gloves and defeated Iran Barkley at the age of 38 for the WBC Middleweight title.
9. Ray Mercer. Was 47 when he last boxed in 2008. IN 2009 he defeated Tim Sylvia in a MMAbout.
10. Tony Tubbs. He wsa 48 when he retired and defeated Minto at the age of 48.
Lennox Lewis
Archie Moore
Bob Fitzsimmons
Jersey Joe Walcott
Wladimir Klitschko
Bernard Hopkins
Vitali Klitschko
George Foreman
Steve Robinson
Carl Froch
Bernard Hopkins
Archie Moore
Mike McCullum
Carlos Monzon
Charley Burley
Juan Manuel Marquez
Lennex Lewis
Carl Froch
Nicolino Locche
Sergio Martinez
Floyd Mayweather
Ray Lenard
Marvin Hagler
George Forman
Lenix Lewis
Rocky Marciano
In no particular order:
Muhammad Ali (became smarter in his 30's)
George Foreman (developed his boxing skills, including his defense, during the comeback)
Evander Holyfield (in his 30's only)
Roberto Duran (became a stylist when he moved up in weight)
Bernard Hopkins
Archie Moore
Marvin Hagler
Azumah Nelson
Chris Eubank
Rocky Balboa (lol)
Henry Cooper, Muhammad Ali, Frank Bruno, Barry McGuigan, Lennox Lewis, Duke McKenzie, Chris Eubank, John "Jack" Broughton, Ted "Kid" Lewis, Bob Fitzsimmons.