Coming in at number 5 is An An Appetite for Wonder: The Making of a Scientist by Richard Dawkins. This is Dawkins memoir and a window into his personal life and discovering what makes this man who he is, love him or hate him, this book will help you better understand what drives him.
 
Book number 4 is a big departure from most atheist, humanist or secular books as it is fiction. Kylie’s Heel by Susan K. Perry is an amazing story about a mother who overcomes tragedy and hardship all without relying on a god or religion. Picking herself up, dusting herself off and living her life. You can read a full review of this book here.