Since you seemed to stipulate that you were looking for classic works based on Shakespeare, I didn't answer before. But if newer or lesser known books are wanted, I can think of only two off the top of my head. Sung in Shadow, by Tanith Lee, a "Romeo and Juliet" reimagining in an alternate Renaissance Italy, and Caliban's Hour, by Tad Williams, which is basically the monster's own version of his life story and the events of "The Tempest." Both of these books, though not well-known, are fine books.
