Most of my list just confirms what others have said....
MK: Columbia Harbour House! (LOVED this! .. though on my 'to-do' list for next trip is Pinnochio Haus)
AK: Flametree BBQ*
DHS: Starring Rolls** for sandwiches if you are eating lunch (they close early)
EPCOT: Tangierine Cafe or Sunshine Seasons
DTD: Earl - this was my first time and the sandwiches were everything I'd heard. Had plans to try WPE but just didn't get to DTD but one time, despite being at POR with the easy boat access....
* AK/Flametree - I've heard mixed reviews, and can be pretty picky about food quality, but thought the BBQ was great. The meals were too much food for one person, especially since I had a 3 year old and a 12 year old with a bird-like appetite. The four of us split a two of the entrees and had plenty.
** DHS/Starring Rolls - The sandwiches we had were good (again, we split since we had an early dinner reservation), and the
DDP meal included one of the cupcakes. We split two meals, cut up the sandwiches and cupcakes into 1/4's and each got a taste of each.