Deal Makers

The Broke and the Bookish asked what books are deal makers. Aside from reviews in Publishers Weekly or Entertainment Weekly that make a book sound intriguing, I'm a sucker by books by an author I already like. I'm also intrigued by historical fiction, especially historical mysteries set in places and/or time periods I don't know much about. Science fiction is pretty much a guarantee I'll be interested, but if a book also has an alternate reality or time travel element, I usually can't buy it fast enough. I'm also a sucker for dysfunctional or emotionally damaged protagonists.

So, what are your bookish weaknesses?