Just visited Durango, and here is the report:
We stayed at the Posada Gorge, a lovely old converted hacienda. The restaurant there serves Argentine-style: waiters circle the room with swords of cooked meat, carving off pieces onto your plate. They claim to offer 21 different swords. My companion especially liked their marinated chicken, pieces of tenderloin wrapped in bacon, and ribs. There is an accompanying salad bar with good french fries.
For beer and delightful snacks we enjoyed the Los Equipales, at the end of Florida Street. Go for a window table on the second floor.
The Playa Azul, a couple blocks north of the Posada Gorge, serves superlative sea food. Shrimp is available in two sizes: regular for $4.50/plate and gigante for $11. We tried the gigante, empanizado and a la parilla, and were delighted with both. Good sides, good drinks, very friendly service.
Gorditas Gambino, on the same street, closer to the hotel, is an excellent choice for light snacks and a wide variety of fruit drinks.
Casa Willander is the place to go to stock-up on healthy home-made snacks for traveling. They custom make sandwitches on breads which they bake, and with their own cheeses. We enjoyed them on our drive back to Monterrey.