The Great Divorce is my favorite book by Lewis. It deserves to be better known.
It does deserve to be better known. I thought I'd read just about everything he wrote until this fell off the shelves at Bookstar one night (in the nick of time, as is so often the case in the stacks).
I realize I run the risk always of mixing my apples with oranges (just ask monkey), but it's this book that made Many Worlds Theory coherent for me ... even if Lewis himself is cautious about the vision of both mathematician (philosopher) and mystic alike.
(Thanks again for the physics lessons, monkey! =)