I see a lot of "almost" bookshelves. They hold books and look "design-y" but they waste energy and space. If you are really into books, it's not about the cute shelves. It's about the books. Make that space hold as many as it can.
Storyline Bookshelf Rack by Frederik Roijé. The rack is shaped like stories are built: There is an introduction, an increase to the climax, and the suspense curve and at the end which is remarked by a short, horizontal ending.