Just got back from a 8 day visit to Mazatlan and had great luck with the food.
The Panama Rest and bakery had a great breakfast. It is very popular with the local I was told. Nice fiestive atmosphere.
On Saturday nights you can go to the Playa Hotel for the "Feista" show which comes witha buffet dinner and all you can drink. The buffet was a mass feeding and so-so. I was told by those in the group that drank that the mixed drinks where watered down. But the show was entertaining with dancers reflecting Mexico's culture.
After the show you can go dance at the Playa Motel's open air dance floor which is open to the beach. this is attached to their dining area which serves a heaty meal and on Sundays a 8 pm they have their own small fireworks display.
Travel to the far north end of the beach to Playa Bruja (Witch's Beach) , there you will find an open air rest. overlooking this secluded part of the beach which specializes in seafood If you plan your dining experience when the tide is coming in you can also enjoy watching the surfers.
We went to Heather's on an evening when they had a show. Heather's promotes the comfort foods that the Americans and Canadians may be missing. At the show it was a buffet of Mexican and Italian food. Not the greatest but I did go back for more and with the show thrown in to boot it was a great experience. heather even came around to see if any of us needed a shawl since it was getting a bit cool as this was outdoor dining.
Las Bruchettas was a great meal. I can't remember what I ordered but it was served in a large bowl made from lava rock. They don't serve wine there so poeple would bring their own. Very affordable. Las Bruchettas is off the main strip, head a couple of blocks east from Valentino's. It is across the street from the "Mega" store.
Poncho's served a good lunch. We stopped in and both ordered the beef sandwich which we could have split.
Also, if you travel a few blocks east of Las Bruchettas there are a couple of open area rest. that were geared now to the locals. I suggest giving them a try.