Breakfast for a Magic Kingdom day you could stop in at Kona in the Polynesian. I know you said you'd prefer in park but this resort is right on the monorail and is so easy to get to MK from here. Their breakfast is really good! For an Animal Kingdom day I'd suggest Tusker House. If you are doing Epcot or Hollywood Studios then Cape May Cafe at the Beach Club is a good stop, or Kouzzina at Boardwalk, a short walk from Epcot. Like a previous poster said, not too many good in park breakfast options.