I liked Joan Didion's book Play It As It Lays but I can't imagine ever having picked it up on the basis of Gene Shalit's* recommendation! Maybe he was less scary in 1970.
This ad is from an excellent New York Times slideshow of archived book ads. It makes me wonder if in forty years, we'll look back and be amazed at how publishers today are advertising. "Book trailers? That's so quaint!" [Via BookSlut]
* For those of you having a hard time placing the name, here's a refresher: