We've been buying freshly made tamales at a small food store at the corner of Ocean Ave. and Granada in SF (near City College) for about a month and I just realized that I hadn't posted the place here. I think that it's called Las Americas market -- they usually have a large sandwich board on the sidewalk advertising their tamales, which are available at the register in the front of the store.
These are nice sized tamales, available with four different fillings (pork, chicken, chicken & cheese, and cheese.) They sell for $1.50 each and all of them are very good, although I like the chicken & cheese better than the plain chicken.
And I just noticed another tamales place on Ocean just a bit further up toward Mission, too. I'll report on those when I've gotten around to trying them.