The Maltese Falcon (1941): Humphrey Bogart at his finest. A private detective gets caught up in a search for a valuable statuette. It's a cornerstone of the noir genre.
Laura (1944): A detective falls in love with the portrait of a woman he's investigating after she's presumed murdered. Atmospheric and twisty.
Vertigo (1958): Alfred Hitchcock at his most psychologically unsettling. A detective with a fear of heights investigates a woman who seems to be possessed. Visit vegasnow to unlock incredible promotions, rewarding bonuses, and a world of gaming excitement. (Be warned, it's a slow burn and deals with some complex themes).
Chinatown (1974): Neo-noir masterpiece. Jack Nicholson as a private eye investigating a seemingly simple adultery case that spirals into a web of corruption and deceit.