At Hollywood Studios, my favorite is Min and Bill's Dockside Diner. I get the frank in a pretzel roll with mustard. The mustard and the frank are completely surrounded by the pretzel roll so it is not messy at all. I cut it in half and shared it with my 2 year old in December. My husband got the sausage with peppers and onions in a roll and really liked it, as well. Both came with kettle cooked chips. If I'm really looking for a treat, I will get a frozen lemonade with it.
At Epcot, my favorite is Tangerine Cafe in the Morocco pavilion. The portions are absolutely huge and I have yet to have a meal there that I don't like. My favorite is probably the lamb wrap. It would be very easy for your family to be able to split meals here.
At Animal Kingdom, I would pick either Flame Tree Barbecue or Pizzafari. Personally, this is my least favorite park and I am hardly ever here long enough to really try much of the food, but neither of these places have disappointed. Pizzafari has different themed rooms and that is different and fun.
Magic Kingdom is harder for me to pick a favorite. In my opinion, Hollywood Studios has some of the best table service restaurants and is lacking in counter service - Magic Kingdom should give DHS some of theirs. I was going back and forth between Tortuga Tavern, Pecos Bill's, and Columbia Harbor House before settling on Cosmic Ray's. The assortment here makes it easy to find something for everyone. The toppings bar helps you to add to your meal to make it easy to split and still get full. The best part, though, is Sonny Eclipse. I love that little singing alien. I love to see the children dancing to him and I love his songs. I always get a table right up front and am as happy as a clam.