I have found the best tamales I've had since arriving NYC from the Tex-Mexico border 5 years ago, and looking all the while. They're available on Saturdays and Sundays at a little combo Mexican grocery store and cafe, called Victoria, between 159th and 160th on the west side of Broadway -- in southern Washington Heights.
They've got two kinds: mole and chicken with green sauce. Both are fabulous, especially the mole. Fluffy, perfect spices, picante but not too much. They cost $1.50 each but are a good deal bigger than the $1 ones you get from street vendors.
Caveat: mole is almost always gone by Sunday -- staff says come Saturdays to be sure some are left.
I am trying to find as many Mexican grocery stores as possible in Washington Heights or points north in Manhattan, which sell good weekend tamales. If anyone knows of more, please advise.