When you're beside the worlds biggest bookstore (namely, "The World's Biggest Bookstore" [http://www.yelp.ca/biz/worlds-biggest-bookstore-toronto]), it'd be easy for people to miss you as they walk by. BMV stands for "Books-Magazines-Videos" and sells both new and used copies of all videos that they have. This appears to be a decent haven for the Nerds among us, as when I lined up to make my purchase, I could not help but overhear three separate discussions about the new Battlestar Galactica series.
You will definitely be able to find items here that are not available in most other similar types of stores. Their 'Comedy' DVD section is the one that got me, where I found not one but two copies of the "ASSSCAT" improv DVD that I stumbled across. Heard of them before? Neither have I. But they were in the Comedy section and it turned out to be fantastic.
This would be a place I'd start if I had hard-to-get books, magazines, or videos I wanted to get my hands on.