2001: A Space Odyssey, by Arthur C. Clarke

I do my damnedest never to include spoilers, though I will reference some bits of the film to make my point regarding the book. So if you've seen it like half the world has, then you've already spoiled some of it for yourself (ha ha). Seriously, I will minimize the spoiler exposure for the rest of you, but that's the curse of reviewing a pop culture staple--it can't be helped.