When my DD was 18, we took her boyfriend, also 18, with us.
That boy loves to eat. His favorite places were:
Beaches and Cream (they ate there 3 times)
ESPN
Boma
LTT
50's
Spoodle's (they ate there 4 times .. 2 dinner, 2 breakfast)
A great place to take a teenager would be the new Earl of Sandwich at DTD. Very good food at decent prices!