After reading some lists from around the internetz, I was inspired to think up my own. I interpreted the question on a personal level. These books influenced me a lot in life, changing the way I see the world, myself and others in the world.
in no particular order...
I was absolutely inspired to write, to to photograph and to play with images and tell my story when I saw this book as a teen. I still keep art journals/scrap books/photo albums or whatever you want to call them and I still cite this book as a major influence as to how and why I make them. I also think that Eldon's journals inspired a curiosity and a longing I have to see the world as a traveler.
I found an old, worn pocketbook version of Radio Free Albimuth in the garage when I was 14 or 15 and from that day forward, Philip K. Dick has been one of my favorite authors and science fiction (particularly the dystopian variety) one of my favorite genres. It's not even his greatest work, it just grabbed me and kept me so absorbed and sort of blew my mind in the way that a battered old science fiction paperback could say so much about the world and human nature.
I read this in high school (for fun, not for school, thank you very much!) and felt so inspired by the adventure and the history of the Beat Generation in general. It made me feel a new zest for literature, life and for my country. I wanted to travel around the country and the world (again with the wanderlust) and I wanted to take pictures, tell stories and meet interesting people. On the Road has help up in rereads, although more recently I read into a lot more layers, including sadness, that I missed as an overly excitable teen.
I first became curious about the Vietnam War in college, when I took a film class on Vietnam War movies. My father, who was drafted and served in the war and never really talked about his experience until he drove me home from college for the summer that year. His stories were powerful and shocking--I had previously believed that he didn't really see any of the scary bits during his time at war. He recommended If I Die in a Combat Zone, a book that shaped the way I now look at people and their experiences. Also a book that sparked a whole phase of reading and learning everything that I could about that time and place.
After being enchanted by the Oz books (and movies!) as a child, I revisited Oz as a teen, reading through Baum's imaginative series repeatedly. I wrote my first term paper in high school about The Wonderful Wizard of Oz...Oz was really the first subject I can remember researching in such a scholarly (by high school standards, anyway) depth. The Oz books showed me that even the most simple children's stories, can be worth a deeper look and a fresh perspective.
Although it is one of my favorite young adult books, Looking for Alaska is here not because I like it, but because I read it at a time when I was still wondering what I was going to do, career-wise. I was already in library school, but I had no committed idea of what type of librarianship I wanted to go into. Looking for Alaska reached me in such a way that it became more clear to me that YA literature would be a part of my life from that moment on. Luckily, the librarianship came along with it, making it a passion AND a job.
A travel guide? Seriously? I know and I put this on here not for the content so much as the story behind how it ended up in my hands. One day, shortly after I had graduated from college and started working an evening job in a college library, I stumbled upon the idea to travel to Belize. Why? I don't even really know why, but the seed was planted and I became obsessed with the idea of going. I had left the country before, but never without a school program or on my own, financially, so it was a big idea for me at the time. After a little internet research, I picked this guidebook and carried it around with me and obsessively studied it for over a year before I saved up enough vacation time and money to go. By the time I went, I probably knew more about Belize, it's bus routes and intricate travel details than anyone ought to! Still, it was an amazing, eye opening experience and, while the book is not the experience, I can't help but think that the careful reassurance of a guidebook telling you that you can do something, even if that thing is strange and new, is sometimes life changing.