That’s a wide open question… are you looking for divey taquerias? High end? Specific dish or region? There is so much great Mexican in this city…

But some of the top:

• Rubi’s – al pastor tacos at Maxwell St. Market (Sundays 7-3)
• Mexique (higher end)
• Frontera / Topolobampo (high end and even higher end)
• El Gallo #3 – carne en su jogo (beef & bacon soup)
• Tio Luis – asada tacos, wide range of affordable, traditional Mexican
• Taqueria Moran – good tacos, wide range of affordable, traditional Mexican, best Tortilla soup in Chicago
• Cafe Lagartia – tacos, esp. fried shrimp taco
• La Chapparita – for tripe tacos
• L’Patron – carne asada or tongue
• Mario’s on west 63rd – al pastor
• Birreria Reyes de Ocotlan – goat tacos
• Carnitas Uruapan and Don Pedros – carnitas.
• Islas Maria – ceviche (they have actual sit down ceviche dishes, but I prefer the stuff they serve as an appetizer which you can buy in a bulk portions, to-go. The fish is basically ground very small, and eat it with hot sauce, limes, and tostados Basically looks like this. havent found anywhere else that makes it the same: https://s3-media2.fl.yelpcdn.com/bphoto/neQgUshWwivO0ltr5nBrfA/348s.jpg ).
• Mixteco – more modern interpretations of classic dishes.

Topolobampo is absolutely amazing if you can swing the price. I did the 3 course option and split a desert and it was more than enough food. They change the menu reguarly so its hard to recommend a single thing, but you really cant go wrong. Will definitely change the way you think about Mexican cooking. (while Frontera is decent, its jammed with tourists and feels kitschy. I think its worth splurging for Topo and the more personalized service/higher caliber dishes).

Also try Birrieria Zaragoza – 48th & Pulaski on the South Side. They serve one thing – Birrieria (braised goat) and the best damn tortillas I’ve ever had. It’s also run by some of the nicest people I’ve ever met (family place).

Don’t let the fact that they only serve birrieria stop you, it is totally worth the trip.

But yea, this is basically tip of the iceberg. We are spoiled in this city, but you do need to go a little out of the way and do a little homework to find the good places. They are by and large not going to be on the north side (with exception of Rogers Park)