Clouter, easily. Had he fought the rematch with LaMotta and found a way to win, his legacy would be head and shoulders above. He's the exception to the rule, I believe, in that his untimely passing didn't enhance his stature but rather stunted it. The primary reason probably being that he wasn't "rock star" young at the time. And being foreign with only a handful of figths in the US didn't help. I'd also pick him to knock Joe out head to head, quite honestly.
Well on paper it's Joe by a mile, but Cerdan was a tremendous fighter. There is no doubt in my mind had Cerdan gone over to the States earlier and made a name for himself, he would have been a huge drawcard and possibly a dominant middleweight champion, and in that sort of company it's saying something. In a way they both left their best work until late in their careers.
