Everyone knows that Blockbuster is only good for current movies and video games. If you want something old, cult following, rare, or foreign, you're gonna need to go to Suspect.
There is a complicated system that I can never figure out, but i just try to go without anything specific in mind and I usually find a gem.
I get all the hot documentaries here.
It's also cheap and you get a password with your membership so that you don't have to remember a card.