I usually get my books from the library so a lot books in my personal collection are books that have been picked up from discount/second-hand shops, from friend's rejects, and library discards. There are quite a few that I actually haven't gotten around to reading yet.
I also have more that's in a storage box and I share a few other books with my sister which are currently sitting on her shelf, so this isn't all of my books, but it's a good chunk of it.