Hi Joyce,
If I were in your shoes, I'd pick the first half of December. I just love Walt Disney Worlds over the holidays; all the parks and resorts are truly "gift-wrapped" for all the guests to enjoy. You can also enjoy many of
holiday activities. It even snows (special Disney snow) at Walt Disney World over the holidays!
If you visit the first week of January, you may be able to see some of the holiday decorations. However, there isn't anything special being offering during that month. You'll find the weather during a December/January visit quite pleasant, but a bit unpredictable. We were just there and enjoyed shorts a few days and needed jackets the other days.
October also has some special events that make visiting then a special experience, such as
Mickey's Not So Scary Halloween Party &
Epcot International Food and Wine Festival. It can also still be warm in the fall with the possibility of tropical storms.
Keeping in mind the unique opportunities, the crowds are important to consider. Overall, you won't find the large crowds of summers and holidays during any of the times you mentioned visiting. A December trip may overlap the taping of the Disney Christmas Parade at the Magic Kingdom, which could be avoided by going to a different park. The Disney Marathon is January 10-13, 2013, which will bring crowds over those dates. However, I think you'll find that any of those times to have lighter crowds, & I wouldn't hesitate to recommend any of those three times.
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