The most memorable books in my life, which have influenced me a lot:
"The Very Hungry Caterpillar" - Eric Carle. How was I supposed to know it wasn't an instruction manual?! I'm still waiting to evolve into Butterfly status and rule Humanity with my massive wings...
"Charlotte's Web" - EB White. Or: "How I Learned To Stop Worrying And Love Spiders".

In all seriousness, it was a book our primary school teacher read to us at school, and despite the sweetness, the sadness, and the Americana of it all, it struck a chord with me. So much so that I bought the book myself later. Sadly my childhood ended (and my arachnophobia returned) sometime in 1991.
"To Kill A Mockingbird" - Harper Lee. Pretty much required reading for everyone (I hope everyone on the BBS has read it, you could learn something

). I was never into books, but fortunately this was another school text, and it did help me understand the world better.
"Sunset Song" - Lewis Grassic Gibbon. A none-more-Scottish text with a somewhat impenetrable tone to the uninitiated, I fell in love with this allegorical school text in the later years.
"Animal Farm" - George Orwell. My first real introduction to the history of the Soviet Union and communism.
"Nineteen Eighty Four" - George Orwell. The first book I actually wanted to read after I left school, I'm saddened I didn't read it earlier. One of the most powerful books I've read.
"Brave New World" - Aldous Huxley. I actually enjoyed this more than "Nineteen Eighty Four", and was well warned from my English teacher that the first part of the book was somewhat confusing and hard to follow. It didn't bother me, and I was well rewarded.
"Stranger in a Strange Land" - Robert A Heinlein. I had heard so much about this book by the "Starship Troopers" author, that I had to try it out. Read it while on my first holiday in New Zealand several years ago.
"2001: A Space Odyssey" - Arthur C Clarke. It changed my whole perspective of Humanity and the Universe. Essentially the story on which "The Very Hungry Caterpillar" was based.
Indeed, you have truly not fully experienced the Three Little Pigs until you have heard it
in the original Walken. 