Purity beat a very young Wlad without a lot of experience at top level. Sanders beat Wlad, who was physically prime, but reckless. Brewster beat Wlad, who was already with Steward, but still reckless. Fury beat a very experienced Wlad, but he was 3 month to 40 and physically deteriorated. AJ fought Wlad 2 years later and Wlad gave it all unlike in Fury fight, but lost after a great effort.
Physically prime doesn't mean "prime" Sanders version of Wlad would have got himself knocked out by Fury by gassing out Wlad gave it all in the fury fight, just because AJ struggled because he's a big stiff idiot doesn't mean Wlad fought better. Wlad knew if he layed it on the line against Fury he would have wilted and failed. He did start to wilt in rounds 10 & 11, the ref saved him with a point deduction because he kept spinning around like a fairy as Fury bullied him in the clinch. The "best" version of Wlad would have been the around 2011 version. 36 years old veteran...but that version still loses to a 2015 Fury. Skills pay the bills. He is predictable, upright, stiff. Why Fury even before he turned pro said he could beat Wlad once he can do a full 12 rounds. Wlad was an expert at clinching and bullying midgets. Couldn't handle two young fresh super-heavys. Remove AJ and Fury from the picture Wlad could have easily reigned over Whyte/Wilder etc. Wilder ducked him. Whyte would have also.
Brewster or Fury. Brewster beat Wlad when he was using his old style, but having lost twice, he should have worked out the bugs by then. Plus he was his physically prime-est. Fury ended the great reign of the otherwise invincible jab-n-grab style.
Sanders and Brewster beat the more athletic version, but Fury who got my vote beat the least beatable version. (Not the least beatable version of his career, but the least beatable among the ones suffered a loss.
Brewster was getting bruised up in there, but he withstood the big punches and kept getting up and was able to pull out that monstrous left hook and wlad couldnt recover. Sanders had a wicked left down the pipe.
In reality, the best version of Wlad was never beaten. He lost in his early days and at the end of his career. In his prime, he was dominant.
Brewster, Fury, Sanders, AJ Brewster beat Wlad at his physical prime but not the peak of his powers with Emanuel Steward as it was just their first fight together.. Fury beat the more highly decorated and acclaimed version but he was slightly past prime.. Sanders beat a green Wlad well before he added Steward to his corner and adapted to his perfect style. AJ beat a well past prime Wlad who still possessed elite skills but could no longer sustain that pace for a while fight..
Fury beat the least beatable Wlad? Wlad had given signs of being shot when he went the distance with Jennings.