Mystery is a large genre, and like fantasy has subgenres inside of it. Here is a quick overview of some of the subgenres.
A previous post went over this subgenre. Cozy mysteries are light-hearted and not as violent or gory as typical mystery novels. They are normally set in small towns and are fun, cozy reads.
Examples: The Thursday Murder Club by Richard Osman, A Deadly Inside Scoop by Abby Collette, Mimi Lee Gets a Clue by Jennifer Chow, and Six Sweets Under by Sarah Fox.
Noir mysteries are on the darker side of this genre. They feature morally-gray characters, urban settings, a dark conflict, and a depressing outlook. This subgenre was especially popular after World War II in France.
Examples: The Big Sleep by Raymond Chandler, The Postman Always Rings Twice by James M. Cain, The Maltese Falcon by Dashiell Hammett, and The Grifters by Jim Thompson.
Spy thrillers are named appropriately: they feature espionage both realistically and unrealistically. They often include global adventure and fictional technology.
Examples: The Spy Who Came in from the Cold by John le Carré, The Kill Artist by Daniel Silva, The Hunt for Red October by Tom Clancy, and The Day of the Jackal by Frederick Forsyth.
This subgenre is a blend of mystery and historical fiction. It’s often based on real-life mysteries, or a fictional crime set in the past. The crimes are typically murders.
Examples: The Shadow of the Wind by Carlos Ruiz Zafón, A Curious Beginning by Deanna Raybourn, The Alienist by Caleb Carr, and Maisie Dobbs by Jacqueline Winspear.
Traditional mysteries feature detectives trying to solve crimes (typically murders) in a small, social setting. The protagonist is often the detective and they solve the crime by asking questions and receiving clues.
Examples: Murder on the Orient Express by Agatha Christie, In Cold Blood by Truman Capote, The Da Vinci Club by Dan Brown, and Death on the Nile by Agatha Christie.