Tezca and Aguila y Sol are definetly two places to check out (neither of them very cheap). I have to agree on the Hacienda de los Morales, way overrated, nice place but so-so food. I would much rather recommend San Angel Inn. Fonda Don Chon is excellent, but it's most certainly bordering on the "exotic". You'll be eating things like bear, lion, armadillo, worms. I would be careful about the street food. For tacos, El Tizoncito or El Charco de las Ranas is worth going to. For other "street food" I would also recommend Maria Isabel (tostadas, sopes, etc).