Alamo Tamales - http://www.alamotamale.com/
They are located on Highway 3 and Clear Lake City Blvd. Next to one of the millions of Starbucks. New shopping strip just south of the Exxon, next to Sonic.
I doubt they make them there. It is a satellite store from their factory, but they are always fresh (delivered every day?)
They have the basics and can special order the others.