Kartchner Caverns area
Tanuki, a Japanese restaurant on Fry (main drag) in Sierra Vista has really good sushi. Marisco's, on Fry near the Fort, is good for Mexican-style seafood dishes. La Casita, Mexican & also on Fry, is thoroughly average & forgettable, as are most all the other places in Sierra Vista.
By the way, Kartchner Caverns is exceptionally good. If you've time, go on both tours.
Head south to the town of Sonoita, which is the head of the southern AZ wine trail. At the crossroads you'll find Canela Bistro, next to the Dos Cabezas tasting room (new releases just out!), which could go toe-to-toe with any of the better bistros on Restaurant Row in Scottsdale. They semi-specialize in local game. Around the corner south from there is the Grasslands Cafe which has a truly stupendous bakery, serve local organic vegetables/salads/sandwich combos for breakfast and lunch. Get some pastries or bread to go.
If you loop around south to Patagonia you run across the Velvet Elvis Pizza Co which usually makes the list of the top 5 pizzerias in the state. Continuing back north from there in Tubac is Melio's Trattoria, where I stop if I am anywhere near southern AZ. The owner is from Rome and very happy to discuss food with appreciative patrons. All I know is the pizza crust is as thin and crackery as I like it and they pull an espresso better than I have found in Phoenix. As a nice bonus, the view is a jaw-dropper, and they don't seem to mind a party lingering.
I kind of love that corner of the world. It may look like a lot of driving from a glance on a map, but if you time things, it's an easy day trip with plenty of local treasures.
Velvet Elvis Pizza Co
292 W Naugle Ave, Patagonia, AZ 85624
3252 Highway 82, Sonoita, AZ 85637
2261 E Frontage Rd, Tubac, AZ 85646