Ther are several factors to consider. Time of year (crowds, park hours), and whether you want to fit in any waterpark time. AK is a one day or less event. MGM can also be done in a day. MK and EPCOT are really 2 day events if you want to see and do most everything. This is considering average attendance. You will not be able to do everything in that time period during say Christmas week. If budget is an issue, you could cut out some attractions and do 1 day AK, 1 day MGM, 1 day MK, 1 day EPCOT, and split 1 day between MK and EPCOT. Also, epcot is a good place to return to in the evenings for dinner and a final attraction or two. Make sure to figure in the fireworks everywhere (AK, MK, EPCOT).
