If you want to take a break from the parks, take the monorail to the Polynesian and have lunch at Kona Cafe. This is one of our favorite restaurants. I think they have the best burgers in WDW.
Another suggestion would be Cinderella's castle. Or if you would like a quick meal, try Pecos Bills. There burgers are pretty good too.
In Epcot, we like to browse in WS and snack. They have some very good vendors such as beaver tails (Canada), Fish & Chips (England), pretzels (Germany), and any thing sweet (France).
In MGM, we have a problem. I really don't care for any of the "fast" options. We always opt for Prime Time.