For me, planning at Disney MUST include the Epcot Food & Wine Festival!! I do not believe i am the only one because they keep expanded out the number of kitchens and days to enjoy.
They have a race weekend as well that includes a 10K and a half marathon. This brings in many, many people as well as the runners. If you plan to go at that time please plan on huge crowds. Eat, drink and be merry!!