While not nearly as exhaustive a list as Vaz I have a couple of books that I would say have a had a lasting effect on my life:
The Farseer and Tawny Man Trilogys by Robin Hobb: I read these when I was in my early teens and perhaps because the main character is about the same age (a little older) in the first book and grew up with a dysfunctional relationship with his father figures I related a lot to his situation. These are the books that taught me about honor, loyality and keeping your word even if it hurts you. I've read the first book (Assassin's Apprentice) about 6 times and later this year I'll go back and re-read them again, I promised myself I wouldn't for several years and now its coming time. I bumped into John Howe in a book shop last year, he did the illustrations for the cover (the cover that caused me to pick up the books in the first place) and I had to go up to him and thank him for it. He was a little skittish at first until I said I was also working on the Hobbit and then he loosened up and we got to talking. Very nice guy and I'm so thankful for his art work.
The Rigante series by David Gemmel: The history of the Celtic people really transplanted to another world. A great set of four books. I think his strongest in terms of overarching story.
Banner in the Sky by James Ramsey Ullman: Later turned into the film "Third Man on the Mountain" a classic mountaineering story.