The Lord of the Rings by J.R.R. Tolkien
The greatest work of fantasy fiction of all time. Though like Gone with the Wind the adaptation of LOTR to film was phenomenal, reading Tolkien's actual words is an experience of itself. Had Peter Jackson created the entire trilogy as it was written, it would probably be 80 hours of footage. The only way to capture the entire Lord of the Rings story is to read it.