Okay, my credentials: I lived in LA for 5 years, which has probably the best Mexican food in America. My favorite taco place is Tacos El Gordo in San Diego, which has 559 (559!) yelp reviews and 4.5 stars; I raved about that place 3 years ago before it blew up. I like lengua, sesos, suadero, barbacoa, al pastor, asada, tripas, carnitas, and buche. I like tacos with pickled radishes and carrots served from trucks parked under LA overpasses late at night.
Maize Mexican Grill is seriously legit. Hand rollled tortillas. Huitlacoche. Huaraches. Rib-eye tacos! The fish quesadilla is incredible: it's a hand rolled tortilla filled with cheese and fish, perfectly deep fried with a delicate crispy outside, a soft doughy tortilla inside.
The atmosphere is awesome, too. At once bright and airy, and cozy too. Sit at the counter and you can't help but talk with Armando, the owner, and your fellow diners about the food coming out. It's more of a foodie community than just a restaurant.
Pro-tip: if you have the time, when you get to order tell Armando that you're in his hands and you'll have whatever he decides to send out. Sit at the counter an be ready to be very happy and very full.