If you are staying at Animal Kingdom and want a truly special dining experience (not in the MK, DHS or EC), Jiko is the answer. It is beautiful, upscale, with warm servers, a wonderful wine list and delicious food.
To answer your direct question - I guess you mean Magic Kingdom, Epcot, and Hollywood Studios restaurants?
Nothing particulary "upscale" at the MK. I would eat lunch at Liberty Tree Tavern, or probably eat a CS lunch there and dinner at a sitdown Table Service at a nearby resort. 'OHana in the Poly would be great, Kona at the Poly too. 1900 Park Faire at the GF if you want characters gets great reviews too.
The "upscale" choice at DHS is the Hollywood Brown Derby. It does not appeal to us and we have never been there. We really enjoy the 50's Prime Time Cafe. The atmosphere is fun, the servers are great and we love the food choices.
We have so many favorites in the World Showcase of Epcot that it is hard to list them. If "upscale" is important to you than Le Bistro in France is your choice. Again, we prefer other places. In no particular order, we enjoy La Hacienda de San Angel in Mexico, the Biergarden in Germany, Teppan Edo and Tokoyo Dining in Japan, Restaurant Marrakesh in Morrocco, Rose & Crown Pub in the UK and Le Cellier in Canada.
With over 100 sit down restaurants on WDW property, a little more info on your desires would help us narrow it down.
Have a Great Trip