Summer Reading

Here it is. This summers reading stack.As is typical it is a random mix of many genres with no real common thread.Just a mix of things just for fun and things for my vocation and things I have been longing to read.Almost all of the fiction are books passed on to me by reader friends, otherwise I would be broke right now. The only thing I am missing is a really great biography.I read a lot of memoir, but it has been ages since I read a biography. Any suggestions?
Also, I have coupon for one free Kindle book, but that kind of pressure to chose is almost overwhelming.So to tell me - what one book MUST I read this summer?
xoxoJ