Cus D'Amato once said about the 1965-67 version of Ali, that "The only time anyone ever touched Ali was when he and his opponent touched gloves before the first round." Okay, that quote is an exaggeration. But not by very much.
Ali, frazier, foreman,Lewis,holyfield maybe and younger less injury prone vitali the last two are maybes
Easy to outbox a "prime" Ali. Headhunter, his competition weren't the best movers and he moved on them. Something Fury knows all too well about.
Best for best, in their respective primes, no screw-ups, I would pick Louis Ali Liston Foreman (first edition) Lewis Vitali Wlad Tyson 50-50 propositions Frazier Holmes Holyfield Bowe Povetkin AJ
Prime vs prime i would say all those named could beat Fury. Sadly i would be hard pushed to say when exactly Fury was in his prime, his defeat of Wlad of course stands out, and Fury beat him in his own backyard for which he deserves all the plaudits, but frankly Wlad on that night was off form for whatever reason. That is not taking anything away from Fury he beat the opponent before him on fight night. Fury would be a problem for any heavyweight champion to face, but likewise these heavyweights champions bring their own big problems for opponents themselves. They sure would be an interesting series of bouts to witness
All of them could beat Fury and i would favor all of them to do so but who WOULD beat Tyson Fury ? Only Lewis and Holmes Kronk Fury would get destroyed by Lewis and bamboozled by Larry Holmes wheras the Fury from the Klitschko fight would get stopped by Lewis in a competitive fight and give Holmes a very difficult night however Fury has a pretty good chance against Vitali. I would make Vitali a small favorite