I don't know if it's "the best" but we sure liked Marakkesh in Morrocco. We also ate at San Angel and liked that. Next trip we plan to try more Epcot resturants like: Le Cellier, Chefs and the Japanese one (our kids want to do that).
Had Le Cellier on my last trip in Sept. and it has become my new favorite Epcot restaurant! WE LOVED IT!
Have also eaten at Biergarten (good for a buffet), San Angel Inn (romantic), Marrakesh (great), Alfredo's (okay, probably not again), Coral Reef (not again--way too overpriced, view of the aquarium is fantastic though), and several of the counter service which were... well, counter service.