The Maltese Falcon by Dashiell Hammett
Farewell My Lovely by Raymond Chandler.
The DNA for modern American detective novels was set down by Hammett and Chandler.
“I got up on my feet and went over to the bowl in the corner and threw cold water on my face. After a little while I felt a little better, but only a little. I needed a drink, I needed a lot of life insurance, I needed a vacation, I needed a home in the country. What I had was a coat, a hat and a gun. I put them on and went out of the room.” — Raymond Chandler, Farewell My Lovely