On his accomplishments in cage if you forgive the steroids and cheating* then there is no argument for anyone else.
Jon got his hand raised in 17 consecutive title fights, 20 overall
He beat Andersons 16 fight win streak in title fights alone.
No one comes close.
* and the refs didn't enforce the rules.
So he played the game as it was played.
It is insane that I don't think he was ever even docked a point for eye pokes. But if the sport basically agreed you get 1-3 free fouls per fight... is it Jon's fault for playing by those rules?