When are you going ? How many days ? Where are you staying ? Is it you the spouse and a teen ? Flying or driving ?
Mickey's Very Merry Christmas Party is this month. Nice for all ages. The teen might like DisneyQuest. A video game arcade with virtual games and a couple of cool rides. One is like bumpercars that you run over rubber balls and shoot them out of a cannon at other cars. The other is my all time favorite ride, CyberSpace Mountain rollercoaster. You choose sections of tracks to design your own ride, then get in a capsule like a VW bug to ride it. You can make it mild to wild with spins, loops, more than a real coaster can do. DisneyQuest is at Downtown Disney. If its nice enough to hit a waterpark there are 2. Blizzard Beach and Typhoon Lagoon. BB has more rides, TL is very sandy with lush tropical foliage everywhere and you can snorkel in a salt water pool with sharks.
There are so many things to do, you have to think about what you want and you can find it there.
I also like the Boardwalk. ESPN Club, Wyland Art Gallery, and a brewery that was good.
For just the major parks, I've never been to the Animal Kingdom, but I heard when they first opened the best time to go is early morning, the animals were more active then. Epcot rocks, go on Soarin' , try to get a reservation in the Mexico dining, its a huge building on the left of the lake as you go into world village. Unbelievable atmosphere, like you are in Mexico under the stars, but you are indoors. The fireworks/laser light show is great too. Close a night there and in the Magic Kingdom for Mickey's Parade and fireworks from the balcony of the train station at the end of Main St., unless the giant Christmas tree is in the way.
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http://allears.net/index.html
http://disneyworld.disney.go.com/