The Prophet by Khalil Gibran. It showed me a new, different way to approach the world, God, and the interactions between the two. Dune. It taught me about political manipulation, sure, but more importantly, that we can be more than the sum of our parts. That we can teach ourselves to be more.
+1 for The Prophet. The trees in your orchard say not so, nor the flocks in your pasture. They give that they may live, for to withhold is to perish. Surely he who is worthy to receive his days and his nights, is worthy of all else from you. And he who has deserved to drink from the ocean of life deserves to fill his cup from your little stream. And what desert greater shall there be, than that which lies in the courage and the confidence, nay the charity, of receiving? And who are you that men should rend their bosom and unveil their pride, that you may see their worth naked and their pride unabashed? See first that you yourself deserve to be a giver, and an instrument of giving. For in truth it is life that gives unto life while you, who deem yourself a giver, are but a witness.You often say, "I would give, but only to the deserving."