The other nine books on this list are fine sources for inspiration or instruction, but the Tao Te Ching is the one I'd want if I was marooned on a deserted island - with or without a golf course - and could choose only one. It's also the hardest one to understand. Deceptively simple in language and as relevant today as it was when it was written, it's a daunting challenge to put it into practice in our daily lives, not to mention in our golf games. You can also throw in the fact that it is the shortest of these books, and it may well be the cheapest if you can find a used copy.