I deliberately missed out the part about covers in this topic from Long and Short Reviews, as I couldn't think of a single book I chose based on its cover. I have, however, chosen a number of books based on their title.
Here Be Sexist Vampires - Suzanne Wright. I had no idea what this would be about (other than sexist vampires) but I couldn't resist a title like that. As it happened, it's a remarkably well written erotic romance with some interesting world building.
In Appreciation Of Their Cox - Janine Ashbless. This is a short erotica about an eight-man rowing team with a female cox, and definitely does what it says on the tin.
Stacy's Dad Has Got It Going On - Giselle Renarde. The title made me collapse laughing - the song is a guilty pleasure for me, and this was certainly a take on romance that I had never seen before. It didn't go the way I expected, but was always entertaining.
So which books did you choose based on the cover or title?