Gee--"best hotel" is a little ....vague.
What is your price range?
What kind of themeing do you prefer? Nautical? Tropical? Woodsy? Exotic? Circus? Old South? Southwest?
What park would you like to be closest to?
How important is the pool?
How many are in your party? Kids? ages? will you want bunk beds?
All of the resorts are decorated for Christmas. The decorations are in keeping with the theme of the resort. GF is all swirly gingerbread-Victorian, Polynesian is NOT red and green, WL is plaid and antlers.
IMHO, the Christmas decorations at WL are incredible. I would take some time to visit a few resorts to see their decorations. You will be blown away.