What is the best burrito place in San Francisco?

A lot of people go with La Taqueria:
http://www.yelp.com/biz/rtGlpEkW1_I4MAdOjhLG3A

They are definitely a good choice.

i love the cancun vegetarian burrito

Cancun for the best vegetarian (you have to love that fresh avocado), Papalote for gringo-style burritos (with IMO the best salsa in town), and Pancho Villa for your overall burrito experience.

I pick Gordos next to GG park.

Cancun is by far the best (especially the veggie burrito!) I'm partial to the Cancun at the corner of 6th and Market - the neighborhood is sketchy, but (surprisingly) I've always gotten better burritos there than at the one in the Mission...

Puerto Allegra, Valencia & 16th.

El Zorro, in North Beach

If you’re willing to venture a bit south into the mission, there’s an unforgettable Mexican burrito stand called El Metate on 22nd and Bryant St. I went there off a co-worker’s recommendation after a beach trip this summer, and the food was delicious and cheap, by city standards. They’re burritos are excellent, and they have an entire shelf of self-service sauces to spice up your meal at the ready.

Parking’s a bit difficult to find, but if you can get your wheels down yonder, you will not be disappointed.