Agatha Christie Books
Before modern crime solving tech-it was about behavior, motive and opportunity! Sometimes they can be a little "dated" and there is a cultural difference, but there is also a wonderful glimpse into the past. Miss Marple has an amazing gift of recognizing trends in people and proves that sometimes wisdom comes with age and observation. I think that is why I enjoy the TV series-'The Mentalist' so much-he looks for small details and human nature.