If Marquez retired now it'd definitely be him, if he beats Pac again and retires it'd still be him, obviously if he loses then not so much
I was just this moment thinking about where Marquez would stand if he were to pack in now. I wouldn't have him top of the tree, I don't think, but he'd be up there imo.
Rocky Marciano...beats Archie Moore by KO in his last fight...retires in April 1956 at 49-0 with 43 KO's...can't get any better!!!