There's quite a few "sit-down or Table service" restaurants which do not participate in the DDP. T-Rex and Rainforest Cafe are those not on the DDP. Sorry

There's many good restaurants at each location if I may say so. What are the ages of your group? mostly little kids? young adults or mixed? more information would be helpful. If you want to do HDDR, it's going to be 2TS off your total DDP credits. Chef Mickey should be fun. If you have smaller children, 'Ohana breakfast or dinner will be great too.
Here's some of our other favorites:
Epcot(Table service): Le Cellier, Chef de France, and Coral Reef(w/o entertainments; just good food)
Epcot(counter service): sunshine seasons, Tangierine cafe
MK(Table service): Crystal Palace, Liberty Tree Taverne, Tony's Town Square
MK(counter service): Cosmic Ray's, Columbia Harbour House, Peco Bill
DHS(TS): 50's Primetime(you will talk about this meal for months), Sci-fi
DHS(CS): Backlot express(my only favorite here)
AK(TS): Tusker House(B,L,D)
AK(CS): Pizzafari, Flame Tree BBQ, and Yak & Yeti Counter service(Yum)