As a PP indicated, there was a thread a couple of days ago about the resort decorations at Christmas:
http://www.disboards.com/showthread.php?t=2709591
There are some pictures in that thread and also a link to a bunch of Deluxe resort photos that I posted last December (post #8).
For the Deluxes, as others have said, the WL has the best theming. The tree was amazing and the "rustic" tones of the other decorations really fit with the hotel. In terms of edible displays, I really liked the chocolate displays of the Beach Club and Boardwalk.
The Pop resort had a couple of trees (one large one in the main lobby, one smaller one in a side lobby, and one by the bell services area), wreathes on the walls in the lobby, and Christmas music in the background. It was much better than at the All Stars, but wasn't that impressive when compared with the Deluxe resorts decorations.
This is what the main tree looked like at Pop:
Over at All Stars Movies, this was the main tree:
And this was the lobby: