Agatha Christie Autographed Display. Agatha Christie Autographed Display She is best known for her 66 detective novels and 14 short story collections, particularly those revolving around fictional detectives Hercule Poirot and Miss Marple. The Guinness World Records lists Christie as the best-selling fiction writer of all time, her novels having sold more than two billion copies. Measures 14" x 17". Comes with certificate of authenticity.