If I'm going to write in the mystery genre, I had best be familiar with its history. I have read widely in the genre, but not deeply and not with any sort of plan. So, I tallied entries from several best-of lists.

• Christie, Agatha The Murder of Roger Ackroyd (1926)
• Doyle, Arthur Conan The Hound of the Baskervilles (1902)
• Hammett, Dashiell The Maltese Falcon (1930)
• Crispin, Edmund The Moving Toyshop (1946)
• Highsmith, Patricia The Talented Mr. Ripley (1957)
• Collins, Wilkie The Moonstone (1868)
• Bentley, E.C. Trent's Last Case (1912)
• Hammett, Dashiell Red Harvest (1929)
• Sayers, Dorothy Strong Poison (1930)
• Cain, James M. The Postman Always Rings Twice (1934)
• Christie, Agatha Murder in the Orient Express (1934)
• Carr, John Dickson The Three Coffins (1935)
• Innes, Michael Hamlet, Revenge! (1937)
• Marsh, Ngaio Surfeit of Lampreys or Death of a Peer (1940)
• Fearing, Kenneth The Big Clock (1946)
• Gilbert, Michael Smallbone Deceased (1950)
• Tey, Josephine The Daughter of Time (1951)
• Allingham, Margery The Tiger in the Smoke (1952)
• Ambler, Eric A Coffin for Dimitrios (1937)
• Chandler, Raymond The Big Sleep (1939)

This list is not the least bit comprehensive. G.K. Chesterton is glaringly absent, for example, because no one agreed on which of his works is the greatest (the votes were split in effect). P.D. James is missing for the same reason. I have read both James and Chesterton extensively (and recently), so I left them off. I have read about 1/3 of those twenty, but not in many years. I had never even heard of several novels on the list, including Trent's Last Case. I'm a few chapters in, and enjoying it thoroughly. If you want to explore best mystery lists yourself, here are a few:

• IMBA's 100 favorite mysteries of the 20th century
• Several lists can be found at topmystery.com
• MWA's Top 100 Mystery Novels of All Time [PDF]