The 50 Shades trilogy.

I read the entire thing in two days during rehearsals in Las Vegas, for two reasons.
1) A coworker kept saying "I'll let you rip on it all you want once you've actually read it," and
2) I really, really hate Las Vegas, so I had plenty of free time.

What did I learn? The writing itself told me that the author had the linguistic skills of a sixth grader, and the popularity of the book told me that the US population has the reading skills and horniness to match.

I don't have anything at all against BDSM. But an unimaginative and poorly written book about a young, naive woman falling for a guy who beats the shit out of her just because he's hot and wealthy should not be on any self respecting country's "Best Sellers" list.