What book do people who do not like the book you like, like the most? Waaah! Let me try that again. You like a book. Other people like the same book. If a lot of people like books you like, you share a taste. Perhaps, then, you could look through these folks’ libraries to see what is lacking from yours. Or you could do the opposite, and look through the libraries of those who don’t share your taste in books. And them new-fangled computers that the people at Librarything own make it real easy to do this on a book-by-book basis.
So for instance, if I tell the Unsuggester to suggest me a non-companion book for Richard Adams’ Watership Down (ooh, bunnies!), I find God. No, really. Among the top unsuggestions for Adams’ masterpiece are: A theology of the New Testament, Daughters of the Moon: Goddess of the Night, some book by Eric S. Raymond, God is the Gospel, and The Google Story. Eery!