Ayn Rands books started me thinking, that was back in the 70s, then in the 80s, I think, maybe the 90s, I got involved with "Neo Tech" and read "Atheism, a case against god" and I think that book, and the philosophy of neo tech allowed me to locate how I stood on the subject of gods, unicorns, elves, werewolfs , and devils. And to conclude how damageing and harmful religions are.

Jonathan Black's The Secret History of the World has many truths between its lines!

There were many but “1984” was most influential. I was a JW and the similarity was so evident. Twenty-five years later “The God Delusion” was instrumental in my finally accepting myself as an atheist rather than just labeling myself an agnostic.

When I was in high school I came across a book by Margaret Meade an American anthropologist, and her writing really started me thinking.

When in high school, I discovered the author, John Steinbeck. A lot of his subject matter is pretty depressing, but yet he captures people as they really behave and are, rather than having happy endings where everyone lives happily ever after. He was the autor who turned me onto reading. The first book of his I read was a short novel called "The Pearl". However, although he is best noted for "The Grapes of Wrath", I think his best masterpiece is "East of Eden," which is actually loosely based on events that happened in his community when he was still a child. He even has himself mentioned as "young Steinbeck" by some of the characters.

One of Steinbeck's books "To A God Unknown" is an interesting story of a man who forms his own personal religion where he worships nature and centers around a tree.

I wish i had read "Elmer Ghantry" by Sinclair Lewis when I was a kid. I tmight have saved me a lot of time in trying to figure things out as far as my personal beliefs as the books portrays religion to be just a money making sham. Sinclair Lewis also wrote "Mr/ Bridge" and "Mrs. Bridge" which basically uses the same characters and really satirizes American life in general. They are both funny and fun reads.

If you like historical fiction, Mary Renault write a lot of great works about the Greeks, Romans and Alexander the Great. I think her best book is "The Persian Boy" which is about Alexander the Great, but if you want to cover his whole life you need to start with "Fire From heaven", which isnt' s good, but highlights religious cults of the time.

Other books... "Brave new World", "The handmaid's Tale" "The Scarlet letter", "Shogun", and I coudl probably go on and on, but I've written enough to answer this question.

Atlas Shrugged. Ok, yes, there are some serious problems with this novel, and I can see why some people really hate it. And in real life there is no blank slate option to start everyone out with similar enough resources and opportunities, and marginalized groups are prevented from being able to become productive members of society by all sorts of institutionalized structures, etc. Still, I read this book several times in high school (I was already an atheist a few years before discovering this book.) and have reread it every other year or so ever since. I read Neothink: Superpuzzle a few years ago, too, a sort of modernized version of Atlas Shrugged with some rather good ideas, but unlike Atlas Shrugged, Neothink is really not available to everyone and thus its message is rather limited, more ego-stroking for rich people rather than world-changing philosophy. I'd rather evaluate the strengths and weaknesses of Rand's philosophy as it appears in Atlas Shrugged and build up from that foundation.
When I dropped out of high school and went to college I did actually major in physics with a math minor, and I was president of the physics club and founder/president of the philosophy club during my first few years of college, trying to follow the path laid out by John Gault, Francisco d'Anconia, and Ragnar Danneskjold. In my defense, I was only 17, and still rather naive and impressionable, so it didn't matter that I had never taken a physics course before, and had only taken half a semester of highschool pre-calculus before embarking on a Physics major.

Chariots of the Gods got me thinking when I was in my teen years. I started viewing the Bible differently and reading from other sources, comparing myths, and questioning, comparing history to what I was reading, and I decided that mankind has been deluded and are being controlled by all the BS.

I really took notice of my religious upbringing and beliefs when I read Mark Twain's "Letters From the Earth" some 50 years ago. Twain, in his usual inimitable and satirical way, helped me to see things through a different filter and I found myself thinking, "Yeah, what about that?" or "Yeah, why must it be like this?" Since then, there have been too many books to count and I have never looked back or gone back to a faith-based life.

Yes! The BIBLE~~~!!!! What a load of mythical crap!!! It changed my mind in that it made me realize how gullible and desperate most people are if they believe the myths put down in the bible. The more educated we become it becomes more and more OBVIOUS this ancient tome is nothing but a storehouse of moral stories told one generation after the other. The bible wasn't even written until 150 to 300 YEARS after the death of Christ!!! How can people believe the stories are real when they were passed on by word of mouth. Personal experience alone proves how unreliable our memories are when we try to simply try to remember what our spouse told us to pick up from the grocery store on our way home from work. Eggs? Milk? Toilet paper? Cat food? If we can't keep this simple little request straight, how in the hell does society think we were able to pass down the "TRUTH" from generation to generation for 150 to 300 years, fer Pete's sake??!! The retelling time after time has GOT to change by just a little each time, ie; we try to recall an auto accident for the benefit of court. Was the car green or blue? Going west or east?? At the corner of 6th or 16th? As unreliable as our memories are stands for EVIDENCE ALONE how unreliable the bible, Torah, Koran or what-have-you is. I rest my case. Amen, brother!!!