Every single reader has a favourite book - just as every reader has books they would never, ever read. We are all entitled to our own reading prejudices but don't fall into the trap of assuming that yours are shared by everybody. It may be difficult to imagine that anyone would want to read a book that you think looks weird or dull but, if properly promoted, every book will find its reader.
When you select books for a display or for a promotion, try and make sure that up to half of the titles are ones you wouldn't touch with a bargepole yourself. This will ensure that you offer a range of readers a range of books.
Why not have fun and test this out? Collect all the books in fiction that you and your colleagues think no-one would ever want to read and make an attractive, face-on display with them.