Read The Black Swan by Nassim Nicholas Taleb (Fooled By Randomness is also good) if you want to peer into the mind of an investor.
Read Hesse's Siddhartha if you're thinking along the lines of culture/religion/philosophy.
Read a few Ayn Rand books if you like libertarianism and don't really care to relate to the characters.
Read We by Yevgheny Zamyatin if you want an interesting allegory that metaphorically compares heaven to a dystopian dictatorship.
Read Unweaving the Rainbow by Richard Dawkins if you're very interested in the sciences.
I remember Sebastian Marshall recommending Musashi by Eiji Yoshikawa -- I'd recommend it too. It's pretty good, and I was especially interested since I've been doing marshal arts for over 10 years now.
And read Surely You're Joking, Mr. Feynman! no matter how you think. It's fantastic.
EDIT: More Books!
I read these when I was in elementary school, but they still hold their value:
The Giver by Lois Lowry if you want more dystopias.
The Little Prince by Antoine de Saint-Exupery if you're feeling especially playful.
The Brain That Changes Itself by Norman Doige. This book will give you a whole new perspective on how your mind and the human brain works! It will talk about neuroplasticity and real world examples of people that had their brain tweaked through this new area of research in neuroscience.
He writes in a direct, no-nonsense way about how he made his millions and he appears to honestly reflect on both the positive and negative results of his wealth. The title betrays the content slightly as it is more about how he got rich.
Gödel, Escher, Bach: An Eternal Golden Braid
Regardless, that book will make your brain fold in it's self. Highly recommended.
I first read it when I was around 14. I think it helped me create a much more complete moral framework than anything I'd heard before (and probably since). Definitely my first introduction to Stoicism.
It's not really a book, more of a collection of reminders to himself, which is probably why it's so useful and interesting.
It took me about two weeks to a month to read and give each question due thought at a pretty leisurely pace, though I am sure most would take many much less time. (I had to stop to keep up on homework/study for tests for about a week of time.)
I don't know if I became a better programmer from it, but it is very much inline with the hacker spirit. You can get it probably from the library/inter-library loan (as I did initially), but you will probably fall in love with it and shell out the $10 to get the used copy.
Hope you enjoy, pwp
"Zen and the Art of Motorcycle Maintenance" had a similar effect, though with the Classicist/Romanticist split more than any other part of the book. Also: "Itty-bitty rules for itty-bitty people" made quite a few things make sense.
1) Hackers & Painters - PG
2) Smart & Get Things Done - Joel Spolsky
3) Rework - Jason Fried
4) Getting Real - Jason Fried
5) Founders at Work - Jessica Livingston
6) Joel on Software - Joel Spolsky
These are by far some of my favorites.
Small Giants and The Responsible Entrepreneur.
I read them when I was young, so more than changing me, they have me a direction and a basis on what to focus. I read some chapters now and then...
This book could/will change the way we see things. Not only for drawing or art, principles from the book can be applied to any creative profession.
Conversations with God (the first book - I didn't get so much out of the 2nd and 3rd)
Flatland, by Edwin Abbott
Gang Leader for a Day, by Sudhir Venkatesh
The Omnivore's Dilemma, by Michael Pollan