The Princess Bride by William Goldman
What a fun book to read. We read this for book club and then watched the movie (which wasn't necessary since we've all seen it so many times we were quoting the whole thing). It is better to know from the beginning that Goldman wrote it all, there is no S. Morgenstern. You feel less duped. I thought it was really obvious that Goldman is the true author (his humor is the same throughout, there's no way the language is from the era Goldman claims it is from), but, I do remember thinking it really was an abridgment when I read it in high school or junior high. And a lot of the ladies at book club didn't know the whole thing is fake either. Some decided they didn't like the book just because they felt deceived by the author.
It is so funny though. And you get all this background information about Inigo, Fezzik and Buttercup. I love the way he tries to place the book in time... "This was before Europe," then later he talks about Paris. Also, when he describes the great kisses since the first kiss was discovered and then says "Before then couples hooked thumbs." The whole thing is funny.
At the end of the newer edition, there's a chapter of the supposed sequel "Buttercup's Baby," along with a bunch of explanations about it. It went on and on... I couldn't even finish it. It was too irritating. Should never have been added, in my opinion.