Interesting things going on at http://www.booklamp.org/,   home of the Book Genome Project.
Stop by the site and play with it a little bit. Plug in some book titles you've enjoyed and see what other suggestions are made.

There are similar projects like this one, but I haven't found any that are so detailed. Instead of guessing what book you might like, it asks you what you liked about the book, and then gives you groups to choose from.

For example, you might have enjoyed the time period the book was set in, or that it was a mystery, or historical fiction. The lists were very long of other books to look at.

If you give it a try, let us know what you think.