I'll preface things by saying I haven't been since 2008 but yes MK is my least favorite park. The entire park is super crowded and the only good table service spot, Liberty Tree Tavern, was greatly diminished when they removed the characters. There are aspects I love (CoP, Space, Mansion, Pirates, Jungle) but there are also some awful stuff/renovations (Toad > Pooh, Timekeeper > Monsters, I don't hate Stitch but Alien Encounter was better).
With all that said my favorite park has been MGM since I first visited it in January of 1991. It knocked off a still very dope EPCOT Center but there is no way a park with Star Tours and Indy was not going to take the top spot with a 14-year-old boy. Add in The Great Movie Ride and I was in love. Even with the awesome stuff that has left MGM (Monster Sound Show, Superstar Television, and the Backlot Tour) they have added to keep pace Tower, Rock 'N Rollercoaster, and Midway Mania. I'm gutted that The Great Movie Ride is closing. That is going to really bug me for a while. When I see MGM next without The Great Movie Ride it will be weird but Star Wars Land and, to a lesser extent, Toy Story Land will be open to soften the blow. I still think I will rank MGM tops. Epcot and Animal Kingdom will be in second and third.