Good question but hard to answer. There are novels that showed me what literature can do and made me wonder if I could become a writer, too. That made me wish I had written them or at least something that was as strong or moving or exciting. 
As for non-fiction:
"A Short History of Nearly Everything" by Bill Bryson which ended my life-long reserve towards science and inspired me to write a novel
"Buddhism Without Beliefs" by Stephen Batchelor
"Who Ordered This Truckload of Dung" by Ajahn Brahm. The title is silly, I read the German translation which is called "Die Kuh, die weinte" (The cow that cried). Wonderful book. 

Veecee: the wonderful thing about the book is that he takes you by the hand and leads you through the history of science by starting in the same place as yourself - knowing very little to nothing. 

I'm a bit embarrased,  but life changing for me  when I was a tot,  were the Dr. Suess books!!   One fish, two fish,.......first one I read.   As I grew older,   The Raggedy Ann/Andy books  took my fancy. 

Oh,  and who can forget those Dick and Jane books in primary school? 

Last edited by sherlockskitty (April 2, 2013 4:40 am)

This thread made me think about many books I've read, so thank you for starting it! I realised that there are many books that reflected my point of view at a particular time, such as "East of Eden" by John Steinbeck. But those didn't change my life, they underlined the direction my life was taking.

One book that really changed something was "The Children of Hamlin", which is a Start Trek novel. It was the first Trek book I bought. I was twelve or thirteen, and have just started watching The Next Generation. I remember the book seller asking me if I really wanted to buy this one, because it was not a book for girls...
That did not only made me aware of how I never wanted to be a girly girl, it also made me a Star Trek fan, what in the end led me to meeting some of the important people in life, such as my husband and my best friend, who is also the father of my Goddaughter.

The other life-changing book was a non-fiction book on plastic. I can't remember the title, but I've learnt about how much plastic there is in our blood and on the beaches and so on. I stopped buying drinks in PET bottles instantly and became more aware of ways to use less plastic in eveny day's life.

Hmmm...that's a tough one. I can think of three, right off the top of my head, but they are probably a little bit of everything:
The Secret Garden
The Stand
American Gods

SusiGo wrote:

Veecee: the wonderful thing about the book is that he takes you by the hand and leads you through the history of science by starting in the same place as yourself - knowing very little to nothing. 

 
Right. I love his mixture of hard fact and humor.
Have you read any of his other books? I've enjoyed several.

Life of Pi by Yann Martel. The ending 's really great, it can actually change the way you look at religion.

For me it's Watership Down by Richard Adams. I loved the animated film when I was a child (I still do, actually), and I've read the book many times. I don't know what it is about the story that touches me so much. There is just so much simple truth in it.

The Doctor wrote:

And then there are, of course, that influenced Benedict and Martin.. just found this gorgeous quote in 'The Hobbit Making of' book:

 
Ok, I am just utterly melting at that.....  how sweet!


I remember often hearing people say 'this book changed my life' and wistfully wondering about that.  Not sure I could say the same... or maybe it just influences me in more subtle ways with something I do or the way I see something, and not changing my whole life.  How did that happen, that one book would affect all their views and habits (or perhaps just propelled them to something they wouldn't have before?)?  Sometimes it's just a really strong message/deep story lodging it's place in one's memory, thinking of every so often.  Such as "The Secret" by Rhonda Byrne re-emphasizing the thought of the power of the thoughts we project.  Or just a fictional story that deeply moved and stayed with for their ideas, like The Time Traveler's Wife, The Night Circus, Raptor Red, Elegance of the Hedgehog, and various stories growing up reading/learning about Egyptian/Asian/Greek mythology.  Ha... I feel like I should break away from my usual sometimes and try more of those deep non-fiction life-changers written by famous motivational speakers!  ;D

The Doctor wrote:

And then there are, of course, that influenced Benedict and Martin.. just found this gorgeous quote in 'The Hobbit Making of' book:

This is lovely. I came to 'The Hobbit' a bit later in life (about 14 I guess) and have always been a bit envious of people that say that were read the book as a child. Although I have read it a couple of times since then I wish it was one of those childhood memories people have.