Truely, speaking none. But if you still insists then pick any two. For e.g. Think & Grow Rich by Napolean Hill and The Magic of Big Thinking by David Schwartz.
Start reading any one of the two. Soon, you will realize that they say nothing new but all common-sense like have a dream, make plan, act on it with perseverance etc etc. Now, once you are over with first one, start reading second one. You will again realize its the same thing as in first book but in different words.
So, all these motivational best-sellers write down the common-sense which is already there in our religious texts - be it any religion. Some authors write directly like James Mason in his book The Impossible is Possible; some uses analogies like Shiv Khera; and some attaches short stories to it like Robin Sharma.
So, don't waste time and money on reading more than two such books.
