This is really a wonderful topic. First a definition of PROFOUND: "Resulting from or affecting one's innermost feelings: deep, intense, strong."

Most of the books that the people listed are well Profound. I have read many of them listed too. Some works not listed: Eckankar, Neo Tech both of which still influences my thinking.

Then there the latest book that I have called MASTER KEY by Charles Haanel. Now, this is the book that Bill Gates got hold of when he was in college. He quit college after just a short time studying Master Key.

It's available on line Free! You have to have Adobe PDF reader and this is also free to download.

Thanks to everyone for telling about their books. Oh, don't forget Alister Crowley stuff too.