With me and music I only need to listen to a song once or twice in most cases before I know it well enough to hum the main melody with no problems, having said that my memory is really bad when it comes to track titles or things like that. So in some ways I'm unfamiliar with a lot of my library, until I hear it. Then I can tell you which band did it or which game it's from, and probably hum it the whole way through.
I try to order from otaku.com whenever I can, they have good shipping and the owner is a really nice guy. They ship by regular post too, which is good for me because I'm never home during the day to sign for packages.