Les Miserables is the longest book that I've read--and I've read it twice!  It's such a good book because it incorporates a variety of themes--it has historical parts, romance, suspense, the love between a father and his daughter, etc.  After you have read this book once, you'll never forget the characters.  I think that, because the book is so long, you really get to know the characters and their situations.  Also, the broadway musical that is based on this book is extraordinary and makes the book become even more alive.