TOD 3:
ChasSmith mentioned movie tie-in paperbacks. I had a few of those. My favorite was Day of the Locust by Nathanael West. I see the movie is now going for $50 for a used Blu and Ray.
I also had one for Rough Cut, which was turned into an odd Burt Reynolds movie. The book featured the first extensive SM scene I think I remember reading.
So many others, such as The Divine Sarah (with Glenda Jackson), Fitzgerald's The last Tycoon, Summer of '42, The Godfather, What's Up Doc?, The Exorcist (hard to hide that one at the Lutheran grade school), and Flowers for Algernon.