A lot of books/movies have influenced me, but here are the most important books that impacted my thoughts:
1. The Bible:
http://en.wikipedia.org/wiki/Bible
I read this when I was in primary school to understand my religion better. I think I read almost half of the old testament before I gave up. I was a pretty devout Christian until I read the Bible
2. The Communist Manifesto:
http://en.wikipedia.org/wiki/The_Communist_Manifesto
A very small booklet. I read this just before the USSR fell. This gave me a whole new worldview. This book gave me the idea that there are more than one way to view things that we take for granted - society, family, religion, economics.
3. The Mind and its Control:
https://archive.org/details/MindAndItsControlBySwamiBudhananda
I received 2 small booklets by Swami Budhananda along with some ICFAI study material. I have no clue about how this was sent along with the study material. Anyway, this helped me understand that I could be my own psychotherapist. This is based on the Bhagvad Gita, and though I am anti-religion, I still think that the Gita is a great self-management/motivation book.
I have moved on since I read these books, and my thoughts have evolved due to so many other influences - but still the influence from reading these books continues to linger....