I think Taqueria Sabor Queretano is just delicious. The guacamole is some of the best I've ever had, and (as mentioned elsewhere) the portions are HUGE. I had an asada gordita, carnitas taco, and chorizo taco - everything was excellent. My only complaint is that they were out of al pastor when we came, but I'll definitely be back to check that out. I've got a longer review on my taco-reviewing website, here: http://tacosmog.com/rev/t/taqueriasaborqueretano.html