When you think about it, I mean REALLY think about it, it may just be the HW division, please hear me out. Maybe not in terms of depth but in terms of justifiable title contenders. At LW no one is going to beat BJ, same story at WW with GSP, sure you can throw someone in there with them but they have very little chance. At MW, you have 2 guys the champ has already beaten and a guy who's won one fight back (not saying he doesn't deserve the shot) but I do think Yushin Okami is being overlooked. At LHW, no one can stack up against Machida. Shogun's just going to have happen to him what happened to everyone else Lyoto has faced and I don't think there's anyone in that division who can really say they could beat Machida. But at HW, Shane could knock Brock out then Nog could submit either of them, then there would be a problem because I think JDS will be next contender after that and he could knock out Nog but they will never fight. Then you have Mir and Velasquez.
So what Im saying is, the HW division doesn't have the most talent but the difference in talent of the fighters is small. The difference between Lyoto and the rest is big, same story with BJ, GSP and AS. Talent-wise yeah the LHW is probably the best, but in terms of how many legit title contenders there will be for each champion in each division I think HW does win that. When you think about it, in the other divisions the real tough fights for each champion are the best fighter in the other divisions. BJ = GSP. GSP = BJ and AS. AS = GSP and Lyoto. Lyoto = AS and probably some HW's.