Jurassic park - I read this in 4th grade. I had a better understanding of genetics then my teachers LOL. IT teaches about chaos theory, and the big question in science :

"Just because we could, should we?"

It touches on greed, pride, and big questions about life. Ive read it probably 10 times.

And, im going to have to say, the LOTR stories, from the silmarillion, the hobbit, to the Lord of the rings trilogy. Long story short, the very few can change the fate of all, the smallest of us came make a difference, and that the smallest, even a seemingly insignificant gift of pity ( as in good), can change the fate of everything, the smallest choices can change history and the world as we know it...