Looking for a light snack in the area around Ratto's (sandwiches were out because I'm recovering from an infected root-canal), I stumbled on the La Borinquena Mexi-tessen on 7th St. (582 7th, next to Mexicali Rose).
It's a bright, clean, cheerful place, with a nice selection of Mexican grocery items on one side (including all kinds of chile-related decor items), and a full taqueria-type food service counter on the other side. I was short on time and cash as well as tender-mouthed, so I bought a pork tamale ($1.39).
I'm not a tamale maven, but this was the best tamale I've ever eaten. The aroma from the yellow masa that wafted up as I unwrapped it was almost dizzying. Since it was too hot, plump and heavy to hold while I was driving, I picked at the masa layer and realized that even if there weren't any filling I would be happy with this tamale. I finally got to the filling -- a generous portion of lightly seasoned finely chopped pork. While not spicy, the meat had the rich flavor of pork that has been roasted rather than boiled or stewed, as I've found more commonly in tamales. If this is a sample of the care and quality of ingredients this kitchen is producing, it is definitely worth a trip back to try the other offerings.
Apparently this place has been there for over 50 years -- but that block doesn't (or at least doesn't now) get much traffic, especially foot traffic (although I guess they get a lot of patronage related to the courthouse/police station/jail complex across the street). Anyone have any more info about it?