We have visited almost every single resort to look at Xmas decorations. The best, IMHO, are (not necessarily in order):
POFQ, WL, VWL, BC, BCV, BWV, GF, Contemporary (though I suspect most people don't see the truly awesome part of their decorations as they are somewhat off the beaten path if you aren't staying at the resort), AK
Fort Wilderness is also quite cool because of all the campers who decorate for the holidays.