I'll go ahead and nominate Brave New World by Aldous Huxley as my favorite piece of literature. I reread it recently (and I'm currently reading Island, its spiritual successor) and while I'd say it's not very well written, the ideas contained in the book are so provocative, I couldn't help but be fascinated by it.
I was in high school the first time I read it and it was the first book I read that managed to capture the ideal I had of a society made into a utopia by using science and technology. It solved the problems inherent in communism by introducing classism--something I regard as intrinsic to human social structures, and it sought to resolve every other part of man's problems via conditioning. Of course the book isn't perfect, but one thought that strikes me still to this day is exactly how much would one be willing to give up to attain happiness? Is the price of attaining happiness the elimination of struggling and conflict--two things which are at the core of the human experience?
That aside, I absolutely love how for Huxley's dystopian novel entertainment was the opiate of the masses.