As a teenager, I would vote for the ESPN Zone and the Earl of Sandwich (good large sandwiches)
Maybe Storytellers Cafe at GCH for Dinner if they are still offering the buffet, also not too child-est in feeling.
Outside the parks, The Pizza Press on Harbor.
Fire + ICE, Johnny Rockets, Cheesecake Factory, CPK and Bubba Gump's at the Anaheim GardenWalk.