Okay, it's a couple hours by plane to this small chain of taco stands at the Southern tip of Baja California, but having eaten there several times during the past 10 days, I have nothing but praise (and a few tips).
Unlike the typical San Francisco-style burrito joint that invites you to order specific meats and accompaniments which you watch the cooks assemble, taco stands in Mexico often give you nothing but a smallish corn torilla topped with one or two battered-and-deep-fried fish pieces, and maybe a sprinkling of uncooked, shredded cabbage. You then heap as much of a wide variety of toppings as you desire and can fit onto your taco. At Super Tacos, choices included a number of different hot salsas, "guacamole" (pureed avocado, really) with and without chunks of onion and tomato, marinated/fried onions in a dark, salty broth, something like cole slaw, and various other things. You can squeeze a lime over it at any point, but don't expect a fork - this is a low budget operation, with fish tacos about 75 cents and shrimp tacos about $1.50.
My favorite protein source was the smoked marlin. I must confess it is incredibly juicy and delicious cooked with equal parts fish and margarine, but if you request "sin mantequilla" in a kind and sincere way, they will make it dry (although it doesn't heat up quite as well that way), and this is much easier on the conscience as well as the body. For 10 pesos, it's a steal.
In Cabo San Lucas, Super Tacos is located well up Morelos, where you might never find it without a rental car. In La Paz, the stand is across the street from the venerable department store, La Perla de La Paz (on the side nearest the bay). We didn't try their stand in San Jose del Cabo.
If anyone knows of a place like this in the Bay Area, let me know!