If you are traveling to the Tampa Bay area (Clearwater, St. Pete Beach, etc) you may want to try a couple places very close to I-4:
Or a place that was featured on Diner's Drive In's and Dives
Danny's All-American Drive In and Dairy Bar:
Neither one is a chain. Brocatos is geared more to our local cuisine (Cuban/Spanish influences)
Danny's is more of an all around sandwich shop with an emphasis on burgers, but with a nod to local favorites.
Danny's also has an old fashion drink box with hard to find brands.