I don't mean an epiphany, necessarily--although that does count. I mean, what books came along and just changed the way you look at things.
For me, (so far) it has been:
Still Life With Woodpecker (Tom Robbins)
The Fountainhead (Ayn Rand)
Maybe it was just that I read them at pivitol points in my life--but both are so valuable to me.
I'd love to hear what all yours are...
Q.