My favorites, broken down by area...
In the Animal Kingdom area: Sanaa
In the Magic Kingdom area: Grand Floridian Cafe
In the Epcot/MGM area: The Cabana Bar and Beach Club (Dolphin, by the pool)
In Downtown Disney: Earl of Sandwich
In the Downtown Disney Area: Olivia's Cafe (Old Key West, although I have not eaten there, yet (we will on our upcoming trip), the menu looks pretty good)