Thanks for starting this thread, because I've been giving this some thought. I'll be in Orlando on business next month and will have all day Saturday before catching an evening flight out. I'm trying to decide what to do with my free time, from where to stay to where to go.
I'll probably grab a one day pass and go to the Disney-MGM Studios where I will be sure to see Walt Disney's One Man's Dream, the Muppets 3-D, and grab a bite at the Sci-Fi Theater. Then, after going through the Great Movie Ride and paying my respects to Clint Eastwood, John Wayne and the munchkins, I will spend the rest of the day going between Rock n RollerCoaster and Tower of Terror.
I didn't get to see the PhilHarmagic on my last trip, though. So, if there is any chance Stitch is open, I might instead make it a day at the Magic Kingdom, checking out these new attractions, and experiencing the mountains.
A complicating factor is the Food and Wine Festival at EPCOT. I did that last October and it was very good. I haven't been through the new Imagination and I might go pay final respects to the balloons at the Land, if it isn't too late, and take a gamble that Test Track won't be broken down, fly to Mars on Mission:Space, then eat my way around the World Showcase where I will be sure to walk from Mexico to Canada this time, so I can see for myself just how visible "Soarin'" is from the other side of the lake. EPCOT is a good park to experience on your own.
One thing I definitely will not do is spend my day at Animal Kingdom. (I'm glad Barnum isn't here to chide me about this). Even though I'm sure the walking trails for viewing gorillas and tigers would be enjoyable, as would the Kilimanjaro Safari ride, that park still ranks fourth out of four. When Everest opens in 2006, I'll be sure to check it out again.