What is the best book you have ever read?

As I continue to read as many books as I can, I am beginning to realise that I really haven't opened my mind and have concentrated on certain genres or types of book.

I mostly have read science fiction and fantasy, have read most of the classics and recently have been reading the best sellers and a few thriller mystery type books!

Therefore I'm looking for a little help on what to choose next and what to read in the future!

I asked the same question on a different site and here are some of the answers - I'll be reviewing some of these as I read them, so check the answers out!