For me it is Sasha Povetkin. Did liked him as a legend amateur and had high hopes and expectations of him as a pro. Turns out he lacks power, a finishing knock-out punch and strategy to compete with the top fighters imo.
Povetkin is not even top5, I don't know why people rate him so high. He has zero chances against Wlad. I remember Adamek said that he actually met Sasha after the Maddalone fight and was suprised that Alexander was shorter than him. He's a short fatty with no real power. I used to hype Proksa after the SS fight. Now I know it wasn't Proksa being that good but Sylvester being that bad. Proksa didn't have a professional team, didn't want to care about diet etc. Proksa's lack of dedication costed him his career. Haye. He could give some big fights. He ended up fighting A-farce, 90-year old Ruiz, Monte and ****ing Bonin. He made a terrible fight with Valuev and forgot how to throw punches against Wlad. This guy sure is a let down.
Right now its Chris Eubank Jr, he might turn the corner as he develops but i so wanted him to be class haha. Maybe not disappointed BIG time, but defo let down. Im still hoping he will come good though, he has time
Margarito - The hand wraps situation . Sadly Even after that , im still a fan of his "either you knock me out or i'll knock you out" fighting style . Margarito was just so damn exciting... Hopkins - Roy Jones Rematch . For those 36 mins i would admit i was embarrased for being a B Hop fan . Mosley - Pac/Floyd fights . Nearly ends the fight after hitting Floyd with 1 punch and then gives up . Wins 1 round against Manny and after hes gets knocked down he turns into Usain Bolt and lets Mannys power discourage him making him quit mentally . Dawson - Pascal fight , Dawson was more talented , had a lot of advantages yet he just stood there and gave Pascal the fight . Then he decided to wake up in the championship rnds . SMH Floyd - Basically for caring about his "0" too much and ducking a lot of fighters due to his fear of possibly losing and of course he will always be held responsible and blamed for Pac fight not happening . That will forever be a huge stain on his legacy . Zab Judah - Lackluster performances which led to losses . I still dont know what the hell happened in the Khan fight .
The Direll's Anthony Peterson Gamboa Donaire is looking worse and worse D Magdeleno Rocky Juarez- Continually Michael Grant- Didn't expect much, really Viloria- Picks me up just to slam me back down Hamed-For quitting after MAB sonned him
For me there's a difference between fighters who failed to live up to their hype, and those who actually disappointed me. To get disappointed you need to emotionally invest in a fighter. For example, Audley Harrison failed to live up to his billing, but I didn't feel disappointed about it. Amused maybe, but never disappointment. The biggest disappointment to me was probably Naseem Hamed. I started following him at an early stage of his pro career, and when he beat Belcastro I geuinely thought the guy was going to be an ATG. He still had a good career, but it never really hit the heights that looked possible in his early 20s.
Mosley, jones, Holyfield continuing with their career. Donaire in the rigo fight. Wished he did more body work
Guzman - professional career disappointment you would think nothing can beat this but see below Valero - personal life/death disappointment ... nothing can beat death but see below Golota - disappointment is his second name (though I'm big fan of him) he still has to live with that Floyd - that a quintessence of disappointment in every inch, you could write wikipedia definition of disappointment == Floyd Maywether and this will stay forever in the annales of humanity