In order of greatness:

-Wladimir klitschko (Ring mag and current linear champ)

-Vitali klitschko (A 3x HW champ)

-Joe calzaghe (Undisputed SMW champ, ring champ at SMW and LHW, one of the longest reigning champion's ever)

-Kostya tszyu (#1 fighter at 140lbs for over 10 years and was the first fighter in 30 years to unify the title's at 140 lbs)

-Dariusz michalkzewski (Linear champ at LHW, ring mag champ from 97-03, and WBO cruiserweight Champion)