My personal list
HW - Either Brock/Cain or Brock/Carwin
LHW - Jones/Gus I, with an honorable mention for Rampage/Forrest
MW - Silva/Sonnen I hands down, though Weidman/Machida was solid
WW - GSP/Hendricks or Hendricks/Lawler
LW - Had it not been for the wars Edgar has been in, I would actually put in Sherk/Florian. But since it's Edgar, I'll say Edgar/Maynard II (with III closely behind)
FeaW - Aldo/Hominick
BW - Cruz/Faber II
FlyW - Johnson/Dodson
WBW - Rousey/Tate II, but that is just the only semi-competitive one we got so far, other than Rousey/Carmouche.