Tolkien created such a detailed world that like a good movie you always pick up something new. And he was middle aged when he wrote it, and now being similar in age you pick up alot more things that he was trying to communicate.
In many ways it's a masterful book.
Another I would rate nearly as high:
Thomas Covenant, Unbeliever by Donaldson.
Six books, I believe.
A little darker - It begins with Thomas Covenant, a leper, believe it or not, whose loneliness, and the strictures with which he must live due to his disease, have him at a considerable disadvantage.
He cannot admit the unreal conditions when he suddenly finds himself to be Barak Halfhand, a hero of the ages in the Land to which he has been transported... Mental instability, which is his bane and an inevitability with his disease, and his first actions taken in the Land leave him unable to accept this reality - and allow him to wield the white gold which is the basis of his extraordinary powers...
The half-hand - a vestige of loss, amputated due to leprosy.
The white gold ring - his wedding ring, which he has stubbornly refused to remove - a vestige of his life before leprosy.
A brilliant mind-f***, extremely well written.