Recently became a big fan of Christopher Hitchens. sadly, somehow, only after his death. Been enjoying many of his quips and debates on Youtube. Eviscerating demolition jobs on belief in the supernatural.'To Kill A Mockingbird' deserves to be in there as it's by far the best book by a female author.
God is Not Great by Christopher Hitchens was the book that had the greatest effect on me.
Sadly 'literary' books are rarely popular books as well. People put them on a shelf but often confess to never reading them.
I'm a big Dawkins fan. Would put "The God Delusion" in my top 10 and saw him at the Royal Albert Hall some 10 years ago. Brilliant mind and scientist. So calm when dealing with nutters. I wouldn't have the patience.