Good counter service:
At IOA -- Thunder Falls Terrace
At USF -- It's a toss up: Louie's, Monster Cafe, Mel's, depends on what kind of food you're in the mood for.
Sit down:
At IOA -- Mythos
At USF -- Lombard's Landing. Or Finnegan's if you like pub fare.
Also, Hard Rock Cafe is just outside a little-known gate near Nickelodeon Studios making it a sit down option when touring USF.