Crystal Palace -- hands down. Convenient location, stay in the park... plenty of variety, higher quality for a buffet - we like the cold salads, salmon, carved meats... everything is good there... plus you get Pooh, Tigger, Eeyore, and Piglet. Does it get any better?
Unless you want to go tour the monorail deluxe resorts, I'd stay in Magic Kingdom and spare that travel time to do more in the park.