Crowds are light - we never wait more than 5 - 10 minutes for anything. If the line is longer when we arrive at an attraction, we just do it later when there isn't a line, LOL! The parades and nighttime shows are crowded, though. Don't mind that.
We enjoy:
MVMCP (MK) - especially the shows and the Christmas parade.
Osborne Lights (MGM)
Candlelight Processional (EPCOT)
Holidays around the World (EPCOT)
Tree Lighting Ceremonies (all the parks & DTD, but especially at EPCOT, which has the Lights of Winter)
Resort decorations - at all the deluxe resorts, incl Swan/Dolphin
Holiday Tag after IllumiNations (Disney did this for the first time last year and it was simply awesome! Hope it becomes a tradition)!!!
Yuletide Fantasy Tour (OK, I think we'll enjoy it, we're doing it for the first time this year)
You are going to fall in love with this time of the year at WDW and see for yourself why reservations are so hard to get at the
DVC resorts in early December. I first went at this time in 1998. Have been back every year since and so far, I just cannot bring myself to skip a year!
Best wishes -