I used to have 5000 VHS cassettes (imagine the space that took up!) but I got rid of those and ended up with around 4000 DVD's. I now have about 3000 assorted BluRays and DVD's (after i moved in with my now wife) and I need a database to track what I already own as I'm prone to purchasing dupes!
But they're alphabetical sorted in clip folders (sans cases) in punched pockets with 4 dvd's to a page.