Have enjoyed Chow recommendations for years and finally trying to give back:
Recent visit to Mexico City with Family, we stayed at Hampton Inn, Centro Historico. Great location, good hotel as well.
First Dinner was at El Huequito, for tacos al pastor and ensalata nopales. Food was good, cleanliness was not, but service was friendly and the meal was a great welcome to the city.
Second day: Lunch at El Cardenal near Zocolo. very beautiful restaurant, but not a great place to bring kids. Staff was stiff and not terribly friendly although professional. Food was good, but not memorable:
Dinner at Cafe El Popular, which is like a local diner again near Zocalo. Aztec soup here is very good.
3rd day: Dinner at Potzalcalli, which is also a simple place for tacos, pozoles, Aztec soup (not as good as Cafe El Popular).
4th day: Dinner at Cafe Al Andar (Chow Hound Recommendation). We impressed our Hotel concierge by asking about this restaurant, which is more catered to locals. The clientele here is young and hip, as is music. Chef came to meet us, and explain the menu. We had chapulines here (deep fried grasshoppers) and also very good ceviche. The chef was proud of the organic ingredients and he used a lot of the flower stamens or pistols that were dried in the cooking and salad as a crunchy and apparently very healthy toppng. Very interesting vibe and meal. We were their with our kids (4 & 7) at ~ 8:30pm, and although we were not the only ones with kids, it is not really a kids restaurant, although no one was unfriendly. It is more like a bar/cafe with men gathered drinking and smoking and couples. My son enjoyed the Chalupines, he is a culinary adventurer.