15 year local here...we avoid chains when we go out to eat...our favorites are Columbia and cafe d'Antonios (both in Celebration). They are both outstanding! Antonio's, an Italian restaurant, has great wood oven fired pizza and calzones. Columbia is an outstanding restaurant (has been in Florida since 1905) with great service.
We LOVE Mexican and it is hard to come by around here...there is a chuys on 192 which is a chain and is ok. We actually drive to El Tenampa on 192 which is authentic Mexican and really great food, it is about a 15 minute drive down 192 east from us. (we are in Celebration.) There is a place called Roccos Tacos on Sand Lake road which is good, but a little too much $ for Mexican in my opinion.
The Town Tavern in Celebration is good too, they have a good Sunday brunch also.
Hope this helps, have a great trip!