MK - Cosmic Rays and Pinochio Village Haus are just "eh", a better choice is Peco's bills if you are in the mood for a decent burger or taco salad (the "fixin's" bar is excellent here) and the best CS choice at MK is Columbia Harbor House for fish, chicken, fried shrimp, salmon, yummy tuna sandwiches, etc. Caseys has yummy corn dog nuggets, but the hot dogs are to be avoided these days, they changed the buns and it is not good!
Epcot- Electirc Umbrella is just awful, AVOID. Liberty Inn and Lotus Blossom are very so-so. Much better choices, Boulangerie for ham & cheese croissants and amazing pastries. Mexico for nachos and churros with warm caramel dip. UK for fish and chips. We also like Sunshine Seasons for the sandwiches, baked goods (strawberry shortcake) and they have a fruit and cheese platter (grab & go section) that we love for a nice fresh snack.
DHS - not much here. Backlot Express is geting pretty decent reviews these days on Allears, but I don't know from personal experience. Starring rolls is always nice and fresh for sandwiches, cupcakes and pastries.
AK - Pizzafari has a decent chicken ceasar salad and the theming is worth a visit, imho. We think the Yak and Yeti counter service is not good at all, except maybe for an eggroll. Our preference in this park is Flame Tree for delicious chicken, ribs and chocolate mousse, hands down.