My Counter Service Suggestions:
If you think you might enjoy a counter-service sandwich that's better than your typical fast-food fare, I recommend Columbia Harbor house in the Magic Kingdom. I recently had their "Starboard Deck Sandwich" which is basically a ham sandwich on a wonderful olive bread with broccoli cole slaw & munster (I think) cheese. It was much more like a sandwich you would expect from a nice deli than a fast food restaurant. I've also heard their tuna salad & clam cowder are very good.
My favorite counter service in Epcot's world showcase is Tangerine Cafe. I like the Sampler platter with Tangierine Couscous salad, hummus, tabouleh & marinated olives.
Oh, and if you like fish & chips, stop by the Yorkshire County fish Shoppe in the UK. (They serve the same fish & chips in the Rose & Crown pub.)
My Sit-Down Suggestions:
If you find yourself on the Boardwalk, try Spoodles. Great atmosphere & Mediterranean menu. You can order a variety of tapas, flatbreads, or a main course. They also offer some great breakfast choices, like Egg Rotollo - Scrambled eggs with chorizo, onions, peppers and cheddar cheese rolled in Lavosh (flatbread) and served with breakfast potatoes and marinated tomatoes.
If you are an adventurous eater you must try Boma at the animal Kingdom Lodge! So many wonderful tastes & exotic foods you've never tried before. (And enough "normal" stuff to satisfy picky eaters)
The Cedar Plank Roasted Silver Bay Salmon at Artist Pointe at the Wilderness Lodge is perhaps the best Salmon I've ever had. Last time I was there my friend and I went for a very late seating around 9:30 pm and we split one Frisee Salad with grilled apples, walnuts and aged white cheddar & one Cedar Plank Roasted Salmon (and 2 glasses of wine). Our dinner was only about $25.00 each and we both had PLENTY of food. Our server was very cool about letting us share, he even had the salad & entree served on split plates. We tipped him generously.
When I travel I like to eat at as many different places as possible and try new foods. Therefore I like to eat lots of small meals throughout the day rather than only 2 or 3 large meals.