Before the division exsisted. Dick Tiger would be my pick, he had to murder himself constantly to get down to the MW limit and then fought to big up at LHW (though he still became champ. He was massive in body and trunk, but without the reach to do the damage way up there. Who do you pick and why?
he was 5'8". I think he would have done well at 168 even though he's on the short side because in the latter part of his career he fought mostly LHWs and did well against them. He even stated in his autobiography that his best fighting weight was around 170. he had to kill himself to make 160.
Bernard Hopkins. He looked great at Light Heavyweight, and probably could have done very well at Super Middleweight as well.
But the division has been available to Hopkins for his entire career. Though I do think it's odd that he hasn't fought at 168 - I guess the fights make the fighter.
Aye, it has been available and he didn't take it, but he still would have thrived there had he taken it up.
For my money, the MW Championship is the most factually prestigious one in boxing. Mediocre heavyweights have lifted that title from time to time, but the MW contenders have generally needed to be useful simply to get a title shot. (Caveman Lee was the only one of Hagler's challengers who clearly did not belong in the ring with Marv going in, and everybody knew Lee wouldn't get out of the first round.) B-Hop stuck to a division he will be well remembered for.