We are only going for three nights in October (right before our four night cruise!)
My kids are 8 and 3. We are doing MK and Epcot. MK is a must do. DD likes Soarin and both of them like the Living Seas.
They like Animal Kingdom, but the hours are short there, and we live close to the Bronx Zoo. If we could not do Epcot, Studios would be my next choice, although it's always only been a half day park for us.