Restaurants are based on your individual preference.   

Besides Yelp, to find the best food in an area, Instagram is your best option.  Also, these accounts have real people running them, don't be afraid to reach out and ask their must-try spots–they will be happy to share recommendations with you.

Google searches for local restaurants and reading the reviews is a fabulous option. 

Opentable is also another source and allows you to book your reservation for most of the fine dining restaurants any region of Mexico you find yourself in. 

TripAdvisor reviews all things travel-related, including restaurants worldwide.