If it's just me personally, that's hard since neither MGM nor AK floats my boat as the saying goes..., if two, then it's easier, though I'm kind of disappointed in the non-direction EPCOT is going these days.
If, however, my wife and daughter were going, definitely MGM, just not enough there for a 2-year-old nor someone that loves classic movies and not thrill rides; however, if we had to miss two parks, it probably would be MGM and EPCOT since my daughter & wife love animals and we both travel internationally so don't need to visit sterilized versions of other countries.
-R