It made me contemplate the nature of reality a great deal. Can't say it's changed the way I've lived my life, but it's pretty good. Also, as far as utopian/dystopian works go, the book builds up a rather great utopia but still manages to trigger its ultimate collapse. I'm a fan of Asimov, so it's definitely a great exploration of his three laws.

The plot of the book, in short, is what happens if a benevolent AI bound to Asimov's Three Laws gains absolute control over matter and energy.