Another tough one for me. In the end, I have to go with Lang's "Scarlet Street". I absolutely loved "Murder, My Sweet" and think it's the finest Chandler to hit the big screen but "Scarlet Street" just proved much more memorable to me. What really tilted my decision was the performance of Edward G. Robinson. Words really can't describe how good and how believable he was in this movie. If you don't feel for him in this one, you have no heart. The ending is grim and unsettling which only ads to the films power and Lang's opening sequence in the rain may be one of Noir's definitive shots.