Just kidding: I'm only reading And Then There Were None. The other two were placed there for glamour.
I've always wanted to be the kind of no-nonsense cool girl who whips an Agatha Christie out of her canvas tote bag on the subway to the secret delight of other bookish passengers. They would immediately know I'm not troubled by an over-complicated life narrative (= "chill") but can balance that out with my razor-sharp attention to detail and a flair for the occasional outlandish surprise, which may or may not include long strangling scarves and a dash of arsenical powder.
According to Nintendo (!), And Then There Were None is the world's best-selling mystery. Wikipedia says over 100 million copies have been sold to date, making it one of the best-selling books of all time. I don't get that shit at all, since it's maddeningly simplistic and more than a little racist, but I'll let you know later today if it nabs me a husband on the C train.