I may be biased since I've been going to this restaurant since I was a kid, but here it goes...
Chapala's is simply put the Mexican restaurant with the best food, the best staff, and the best margaritas in town. Their Grandpa margarita has been a staple since I've turned 21. Their waiters are always friendly and have not changed for years, they love their jobs and their customers, and it really comes through in the service.
The meatball soup or anything with shredded beef are the best things to get here, but pretty much no matter what you choose it will probably be a winner.