How about Augustus himself? Fan favorite, definitely, but not "great". Has the baffling drunken moves too. Although, i think opponents know that if it goes the distance, Augustus won't get it.
Luis Collazo? Arguably beat Hatton and Berto.... gave Mosley a bit of grief before having hand trouble.
as homicidehenry said, george "scrap iron" johnson was a great mention. such a brave fighter that he received a medal of valor from the international boxing hall of fame. maybe micky ward may be a fit in this thread, not scorecard wise because on record it doenst appear that he was in the fight with zab judah, but according to zab judah, his left hook to the body was crippling (like a knife stabbing). antonio diaz, james leija and arturo gatti where given all they could handle (and maybe more) against ward. robbie simms was a danger to many of the top fighters in his era beating some or at least giving them scares; doug dewitt, iran barkley, roberto duran and nigel benn.
Harold Weston is one he gave Hearns all he wanted,was competetive with Cuevas before getting his jaw broke, Had a draw with Benitez,Hedgemon Lewis,and stopped Vito Antufurmo. Oba Carr was also competetive with a prime Oscar,Tito,and Ike quartey and whipped Yori Boy
hopkins, roy jones had the most decisive victory against him but it was still jones's closest fight to date since jones didnt even lose rds back then.
Jose Ribalta. The dude was no doubt a journeyman, but man did he put up some tough fights. He took some of the biggest shots a prime Tyson ever delivered like he was on PCP. Lost many close split decisions against top talent---Bonecrusher, Marvis Frazier, Whitherspoon, and Dokes.
In his prime Ruben Castillo was a tough fight for legends like Arguello and Sanchez. His fought Arguello on even terms until getting stopped late,and his fight with Sanchez was a lot closer than the cards had it,some said it could have gone either way. Albert Davila was always another tought fight for the Champions of that great bantam era. SPlitting 2 fights with Pintor beating Rodolfo Martinez,giving Zarate a good fight,losing a split to Jorge Lujan, Beating Frankie Duarte,Albert Sandoval also was competetive with Wilfredo Gomez before getting stopped late. Finally won a title in the tragic fight with Kiko Bejines. Was past it when he lost the title to Miguel Lora(another excellent fighter)
What about Harold Weston another New Yorker who was around at the same time as Mamby? No body ever had an easy time with Weston.