If you read reviews on Chowhound or other food oriented sites, you already know that Puebla Mini Market has a reputation for amazing tortas. What keeps it from being swamped with Torta Tourists is that the sandwich counter is all the way in the back of the market. However, as The Village Voice points out, the journey to the back of the Mini Market is worth it.
Check out the review, and then pick up a torta from Puebla some time soon.
The same reviewer gives some attention to another Sunset shop: New Public Meat Market. It's called an adventure...but really it's just a shop, like any other, but with more meat choices.