I am very jealous. My husband and I go every October for three weeks and that seems very far away right now!
You did not mention what kind of food you are looking for so with that said, I will tell you where we like to eat bearing in mind we try to eat more like the locals and less like tourists. We were turned on to most of these places either by our friends who live there (Mexicans) or ex-pats who are now living there. I am sure there will people who disagree with me but I am just letting you know what we like. Everyone has different styles and tastes.
In the downtown:
Las Braseras - in the evening, Taco Pastor. You know they have it when the big pork is on the brasier (not sure what it is called) out front by the sidewalk. If you haven't had it before, it is small corn tortillas with a little of the pork, some pineapple, cilantro and onion. Killer! Last year a friend turned me on to their fish tacos. Three for 55 peso. The fish is fried in fairly good size chunks, put in flour tortilla with cabbage and kind of a coleslaw sauce. I had it three times last year and it was my "we have to go to the airport so what is my last meal" meal. A lot of people think La Serena Gorda on the fishermans walk (by the pier) has the best fish tacos, but I beg to differ. Although theirs were fine, I thought they were overpriced for what you get. Try both yourself and decide as that is half the fun, right?
Tamales Any y Atole - On a corner with a huge thatched roof and painted yellow. It is across the street from the big night club Sacbe's and diagonal from the little bar on the corner with 4 barstools in front of it. I haven't had much there but the tamales and they rock. Large, well filled and last year they ran about 15 peso each. One is a meal for me. I like to order them "para llevar" (to-go) and reheat them at home for the next day or two. Make sure you try some in the banana leaves and one of my favorites is queso/epazote and the squash blossom and queso although they are all good.
On Nicolas Bravo, there is a place locals refer to as Pozole Alley. It is not much during they day, pretty quiet but in the evening all of the tables and chairs come out and you will see tons of local families eating there. There is about 4 or 5 restaurants down it and we like Ricomar's (about 2nd or third one in). Don't miss Thursday night pozole. It runs about 30 peso for a big bowl of pozole with all of the trimmings. Yummy! Pozole Alley starts next to the big raised restaurant Viva Mexico and runs south to where all of the buses park along the canal). It is pedestrian only.
I won't be able to give you directions but if you ask I am sure one your favorite bartenders/server/store owner or hotel worker can give you directions to Dona Leche's.
This is the one behind the Mercado, not the "to-go" one in town on the main road. It is only open for breakfast (haven't made it there that early) and lunch until 6 pm. It really is worth the trip. I have never had a bad meal there and again, very inexpensive. Make sure you get the beans. They are whitish and thin, but ooooh so good with the homemade corn tortillas! One of our friends even went and bought the tortillas to take home with her on the plane! It has a dirt parking lot next it and you won't see many gringos there (except the ex - pats that know about it) but lots of locals. Our friend who is a local usually chooses something for me off the "daily special" list at the bottom of the menu. A little spanish helps but the servers seem to speak a bit of English. Really, don't miss this place. If you see the big circle that cars go around and are facing towards the ocean, it is the top road on your right where the car dealership is. Head north from the car dealership to your first street on the left and Dona Leche's is on your left a block or so up. I know there is a nice bakery across the street. As I said before it has an empty dirt parking lot next to it.
Speaking of bakeries, if you find Tamales Any y Atole and head up the street toward the beach, it is on your right. Hard to miss as it is painted pink. Sylvia owns it and make really good pastries and breads. This is on my shopping list about every other day. I can buy decent Mexican pastries here in Seattle but don't let myself as I don't need the fat and calories, but in Zihua, all bets are off!
Those are our go-to places. I have also heard good things about Mango's and Banana's (I believe they are both on Nicolas Bravo) and Pollo Loco is good for a char grilled chicken dinner.
For higher end fair, Coconut's is right in the downtown (by the pink bakery) and the menu is posted at either entrance. I hear the food is good but if I wanted to pay those prices, I would stay here in Seattle. A lot of people love it, we are just not into spending that much. Again, with that said, last year some friends of ours were leaving and wanted to do one nice dinner. We went to the Kau Kan (were able to get in without reservations although they are recommended) and had a beautiful dinner for four. The dining room is on the roof with an incredible view of the bay. Make sure you hit it at sunset if you go. I am attaching a photo we took when we were there. I would go there again for a special occasion. I think we spent $170US with a large tip and that included a few tequilas at $10 apiece. Still not bad for a really nicely prepared, served dinner with great ambience. I heard Il Mare is also outstanding but haven't been there.
The KauKan is on the road from Playa Madera to Playa La Ropa just at the top of the hill from Hotel Irma.
Well those are my recommendations. Hope they help a bit! Have a great time it is a wonderful town!
I just spent 10 days in Zihua staying on Playa Ropa, so I've got a few places to add.
If you're on Playa Ropa, Dona Prudencia is probably your best bet. It's mid-range prices; definitely costs more than the local joints, but not pricey by American standards. I think most entrees were in the 80-120 peso mark (13 or so pesos to the dollar when I was there). I loved their tortilla soup, especially with a squeeze of lime added. Patty's is also pretty solid (best limonada on the beach, excellent chilaquiles), same price range, but be warned: service there is SLOW. Any lunch there will be a leisurely one - though if you're on a beach in Mexico, what's your rush?
In town - We had a heck of a time finding Dona Liche's, but like Jody says, it was pretty excellent, and cheap. For Thursday night pozole we went to Cenaduria Antelia, which is the first restaurant on Pozole Alley, right next to Viva Mexico. I got the red pozole, which was delicious, definitely had a little kick to it. The green and white versions went over well with my family, but I preferred the red. Enchiladas were also excellent, though the tamale was a little bland. The bill for 5 people, with 6 entrees and a pitcher of jamaica (hibiscus tea), came to 190 pesos (about $15) plus tip. I'd definitely recommend a meal there.
An update on Tamales Any: seems they're going downhill these days. We went there one evening after much anticipation (my parents ate there last year and loved it), and we were all disappointed. We ordered a variety of tamales and an order of enchiladas, and none were very good. I'm told the margheritas were also off. On the upside, they had the best limonada of the trip, and they might be worth a trip just for the bathrooms (beautiful painted ceramic toilets, sinks, etc).
The best meal of the trip: There's a little place called Ruffo's across the canal from the main downtown that's just amazing. We got there from hotel Sotavento by walking on the main road down the hill above Playa Ropa towards town, turning left down the steep hill at Hotel Irma, and following that road straight to it, and it's just past the dirt lot with the giant tree and before the footbridge into town. Or just ask any cabbie. They have a pretty short menu - a few kinds of fish, shrimp, chicken breast, quesadillas - and just about everything is cooled the same way on the grill with butter/oil and herbs, and everything is just mindblowingly good. (Most dishes come with guacamole, beans, and french fries, none of which are that great, but who cares.) I got a chicken quesadilla, which was a chicken breast grilled with all the herbs and such, sliced up and put inside a tortilla with melted cheese. It was *amazing*. Most of the rest of the group ordered seafood, and the whole table was literally moaning in pleasure. I'd go back to Zihua just to eat there again.
Most beautiful meal of the trip: Amuleto, high up on the hill over Playa Ropa. This place is uber-pricey, but if you're not up for a splurge i's worth going for drinks to watch the sunset. Most beautiful view ever out over the bay, gorgeous garden setting with an infinity pool going over the edge, and very good food, sort of high-end Italian/Latin, definitely with some Brazilian touches. I got an incredible tomato/basil cream soup, followed by pasta with vegetables and chicken. The rest of the table got tuna carpaccio, shrimp & lobster risotto, and mango-lime shrimp. They also gave us an amuse bouch and coconut sorbet between courses. The consensus was that the food was very good but didn't quite live up to the setting or the view. Chocolate mousse for dessert was forgettable. Entrees were 180 to 320 pesos (about $14-25).
And just a warning: I'm now on my 8th day of an unpleasant case of "Mexico belly," which I'm told can recur for a few weeks. Who knows if it's from something I ate, an unfortunate gulp of seawater while snorkeling, bad karma, or what, but it drives home the lesson that you have to be very careful down there. Only drink bottled water, don't eat any produce you can't peel, wash your hands often (I recommend Purell), and bring a stash of Imodium just in case.
If you've had stomach trouble for over a week, it's probably a good idea to see a doctor. "Turista" is usually over after a day or two and doesn't recur.
If you need immodium while you're in Mexico, it's readily available at any pharmacy, ask for IMODIO (ee-MOH-dyo). It's very inexpensive, and no prescription needed.