Chayito's burritos-San Mateo/San Carlos
On your advice, I did. Really tasty, thanks! I'll definitely be going back, and it's up there among my favorites in that area. The other that comes to mind is La Azteca in RWC. Different styles of burritos, but I've been going to La Azteca for many years.
However, may Chayito's rest in peace -- still unsurpassed, in my book.