I assume you mean Universal Studios Florida (USF), in which case the best place to eat is Lombard's Seafood Grille, especially for the fresh seafood, which is the priciest thing on the menu. Great ambiance, good food, and a spectacular dessert called the San Francisco Foggie (a brownie sundae).
If you prefer a pub-type atmosphere, Finnegan's is the other choice of sit-down restaurant.
If you go to Islands of Adventure, thenm the best pace by a wide margin is Mythos.