I think probably SRL, he was excellent in-ring but lost on his biggest night vs Duran and got a gift vs Hagler and then Hearns. He was good no doubt but not even close to top 20 for me.
Danny Jacobs too hyped in my view as he is good but come on son Dirrell brothers AJ at HW Danny Garcia was for some time Spence Lomo
Sugar Ray Leonard ... also, I have no idea why anyone has ever paid a cent to watch an Adrien Broner fight. Not only is he not that good, he's boring as hell.
These aren't the most overrated ever, idk the answer to that, but some who were quite overrated imo: Gassiev - I like him & he is good, but not as good as the hype. His power is crazy but not sure his boxing ability is good enough to warrant the hype he had/has Eubank Jr - The hype was just stupid a few years ago. Luckily it toned down a bit Crolla - Don't think many actually do rate him, but somebody must rate him to give him chance after chance at world level.