Gone Girl, by Gillian Flynn

Excellent dark psychological thriller. Worst. Marriage. Ever.
Flynn's elegant style and endless twists make her one of the most interesting thriller writers around, and this (for me) tied with Dark Places as her best.

Dark Places, by Gillian Flynn

Wonderful, very dark and gruesome. Libby Day was 7 when she was the sole survivor of the murders of her mother and two sisters, and based on evidence she gave, her 15 year old brother Ben was convicted of the very violent murders. Now as an adult, the last of the sympathy fund that had been established for her has run out, and she has no life skills to earn a living. A group of true crime enthusiasts offers her money to tell them about that night, and she begins to explore, for the first time, the facts of the case, and to find out what really happened that night. This was pretty fantastic, but disturbing- not for the squeamish, but a really well written take on a very unsympathetic character and a wonderfully plotted story.