When this subject comes up Jerry Quarry is always my first choice. If Jerry were around today, he would own the cruiserweight division.
from my era(i am only 22) the most obvious choices are david tua, ike ibeauchi, rocky juarez and ali funeka.
Pedro Montanez back in the thirties, only eight divisions back then and a top ten atg was in his prime .........a guy by the name of Armstrong and so Montanez who could have been a champ in any other era went without.