For me it's Sonny Liston. Awfully poor resume for someone who is considered an ATG and dominated in a poor era. His strength and power was massively overrated and blown out of proportion. His fame is the result of Muhammad Ali and George Foreman's remarks on him and his mob ties.
For me it's david tua. He was not "The next elite heavyweight champion or the new Mike Tyson" everybody made him out to be. He is incredibly overrated. He wasn't that skilled. Granite chin and strong knockout power, but wasn't exactly a technically skilled boxer not that fast or elusive. Almost impossible to KO but can be outboxed if you have the skill. He was not an evolved or stronger version of Tyson or frazier. He is not Mike Tyson and he is not joe fraizer, not even a fat version.
Bowe. Some people think he walks on water but he's really got only one A level win and that is Holyfield, a much smaller guy that played his game. A lot of the other guys he fought were light hitters or limited in other ways. If he'd fought and beaten Lewis I might buy the hype but instead he dropped his belt into the trash.
By the way, i don't see anybody overrating Liston's power and strength. He is regarded as one of the hardest puncher in boxing history, because he is. Some people has stated he was a harder puncher than George Foreman. He is regarded as one of the strongest, if not THE strongest man in boxing history, because he is. Foreman said only Liston managed to physically overpower him and force him back. Liston couldn't use a time machine in order to get Lennox Lewis or joe fraizer or Mike Tyson or Joe Louis in the ring with him, he fought whoever was willing to fight him. He was really avoided at his peak.
Ali. He was a great boxer, but not the greatest. Instead he has become a kind of deity for many of his fans of him.
well you'd have to say Ali, because his Persona self perpetuating character in what was the beginning of the age of Media Made Celebrity, which of course still exists today, but was much, much less and influential pre 1960s. However in fairness to Ali, he was without question a 1st Class Boxer, who proved to be both durable & tough, as well as his self believe and drive which was evident in a few exceptional victories. a True Legend, though I believe Joe Louis deserves TOP Spot. MOST Overrated, regretfully, because he is a likeable good hearted man, but a 2cd Rate Fighter (not his fault), but it is the whole New Sub Par Division of SUPER Heavyweight, and that is TYSON FURY!!!
It's hard to overrate the guy with the greatest record in his weight class. For every fan that thinks he's the absolute best and untouchable, you have fans claiming he was weak, a poor puncher and that Tyson, Bowe, Lewis, the Klits and all other HWs since the 90s beat him. By definition, this balancing of hyperbole means that he cannot be overrated.