Well Vitali and Wlad Klitschko both have a PHD in Sports science, so I'm thinking they might have the most impressive CV
Current fighter...Hopkins Pavlik, Calzaghe, Wright, Tarver, taylor, Dela Hoya, Trinidad, Jones Junior are the main one that come to mind. Some of these he did lose..but they were mostly very close loses. I know everyone slags PBF but Corrales, Castillo, Dela Hoya, Marquez, Hatton, gatti...if he adds Mosley and Pac it will be up there with Hopkins...thats a big IF.
Winky Wright has Paul Williams, Hopkins, Quartey, Taylor, Trinidad, Mosley, Vargas, McKart which is not bad at all.
jermain taylor has bhop x2, pavlik x2, winky, spinks, froch, lacy (i know but still...) which isnt as much as some of the others listed but when you factor in he has three fights in this super six w/ some quality fighters, he should be up there soon
James Toney is up there, there's no denying it, 80+ pro fights in 5 divisions, against a who is who in every division (except for the Klits at HW), never been stopped or being close to being stopped, yeah I know he lost some and had some bad nights, well it's an old school resume, bla bla, you know the deal... The roids tainted his legacy somewhat, but not his record. Check his record at boxrec, you'll know what time it is.