I like the Hitchhiker's Guide to the Galaxy. While I think it would help if Mr. Adams had toned down his risque language in some places (much of it was superfluous and unneccessary), I find the adventure entertaining and sadly prophetic.
Interestingly, two years before I read Adams, two years before I even knew what postmodernism was, I wrote a small essay on how weirdly coincidentally unexplainable my life is.