my daughter found a book one time and came to me with it, saying 'dad, you might like this. its got chapters.' the book was 'that dark and bloody river' and it made the most drastic change to my way of thinking since the bible. it charts the ohio river valley, from pittsburgh to st. louis and all the attrocities that occured there over several hundred years.

I read "Stranger in a Strange Land" when I was about 13. I think it was my first "grown-up" book. It most definitely changed the way I thought about religion. I realized that I wasnt the only one doubting an omnipotent, infallible deity.

Two from Lawrence Krauss;
The Physics of Star Trek.
and A universe from nothing.

A Brief History of Time from Steven Hawking.

Pale Blue Dot: Vision of the Human Future in Space by Carl Sagan.

there are probably a few others, but i can't remember atm.

To kill a mockingbird,stranger in a strange land, shogun.

"For me it was Dune, Stranger in a Strange land, Foundation trilogy "
.. > all of those were awesome but the by far biggest influence was Stranger in a Strange land

"Novels" do/did not change my way of thinking...they are by definition, fiction.

The Age of Reason - Thomas Paine
Freakonomics - Steven Levitt & Stephen Dubner
The Creature from Jeckyl Island - G. Edward Griffin

Many.

1984