Past 5 I'll go with Canelo. Not trying to get into the whole 155 BS, but I just think his resume doesn't merit his paychecks. He lost to FMJ (badly) and he didn't look super good against anyone really good.
Bute, pac, martinez, marg and williaMs. All decent lower level B on their best nights. I'm sure I'm missing something. To be added, porter, thurman and fury
David Haye deserves a mention. The hype before the Klitschko fight was unreal, people thought that he was the toughest test of Klitschko's career and what not. Went missing for years and is now fighting much lower level of competition than expected. I'm not saying he's a bad fighter and I like him, but we're talking hype vs actual skill/resume ratio here.
Who is or was not badly overrated: Pacquiao Mayweather Calzaghe Hopkins Cotto Haye Klitshkos Who was/is overrated: Lacy Abraham Roman Gonzales (I know a lot of you won't agree here - he is good, but not p4p king level - I think Inoue will eat him for breakfast)
Cotto is a good call. He was mentioned among the best boxers of this generation but what has he done to deserve such honour really? Most of the hype was because he was from Puerto Rico.