What are some fun restaurants for a sweet sixteen dinner that are not too expensive? ?

Mexican fiesta !!! Cold beer! loose women that will do your girl and it's cheap !!!

Dave and Busters, or a pizza parlor and if you are going to have  10  or more people in your party, you should call ahead 

I would go with a family owned pizzeria ~

Chipotle caters for all types of events. Kids can make their own bowls and they provide you with all the necessary cutlery, dishes, and clean up material. You literally have zero dishes and can throw it all away within seconds.

Find a themed restaurant. They cant drink so dont take them a tiki bar obviously. Dave and buster's works, pizza place with an arcade, I had mine at Kobe steak house. It was entertaining and delicious, though a bit pricey. Hard rock has a fun theme, or really anything off the beaten path. We have a horror themed restaurant here that could be a hit. Maybe an all ages comedy show or concert? Any festivals happening? That's entertainment and while it's not quite dining theres generally plenty of good. Skate rinks or bowling alleys? Basically the goal is to keep them distracted with activities until the food comes. Lol c

Dave and Busters 

Italian would work, or try a Basque Family style, everyone orders their favorite main dish and they bring numerous side dishes like salad, soup, shrimp potato salad, cold cuts and bread, it's fun, they load up the table and everyone digs in.

Dollar menu at Wendy's, McDonald's, or Burger King

Peter Piper Pizza

Hooters. The guys will be happy and the girls will have something to prove.