You can't go wrong with any resort or park. ALL parks and resorts are decorated beautifully. For a resort, we particularly like VWL.
Things not to miss in the parks:
1) MK Lighting of the castle with icicle lights - magnificent - beyond description
MK Wishes Fireworks display
MK - if time and money permit, Mickey's Very Merry Christmas Party.
2) DHS - as other have said the Osborne Lights are well worth seeing
DHS - Gospel Choir - as long as you're there
3) EPCOT - Lighting of the Archway and Christmas Tree
EPCOT - Candlelight Processional - for us, this is a can't miss!
EPCOT - The
DVC (if you're members) Merry Member Mixer just outside the International Gateway is GREAT!
There are many others, I'm sure. These are what I'm remembering too close to my bedtime..... Night Night!