Agatha Christie/YMMV

• Complete Monster: So many examples, you'd need an entire page to document them all.
• Hilarious in Hindsight: In the short story "Mr. Eastwood's Adventure", written in 1924, the title character cites Murder Most Foul as an example of something that would be an awful title for a work. When Christie's novel Mrs. McGinty's Dead was made into a film in 1964, the producers, by sheer coincidence, chose to change the title to Murder Most Foul.
  • The short story "The Rajah's Emerald" has, as its hero, a rather nervous weak-willed young man who solves the case more-or-less by accident. His name? James Bond.
• Magnificent Bastard: The Secret Adversary, N or M, Curtain
• Nightmare Fuel: Part of Christie's genius showed in that anyone could be a suspect, whether they had a bulletproof alibi, were hopelessly in love with the victim or weren't even there at the time. One of the most horrifying aspects is that so many of the murders are committed out of love, or by people who truly loved their victims.
• Recycled Script: A number of short stories were later expanded into novellas or full novels. Three of the four stories in Murder in the Mews are expanded versions of earlier short stories.
  • Lampshaded in Cards on the Table, in which Ariadne Oliver admits that her stories are exactly the same.
• Seasonal Rot: Christie's last few books, when her talents were clearly starting to slip.
• Seinfeld Is Unfunny: Many of the twists that Christie invented have been copied so often that modern readers, upon reading one of her famous novels, may be left wondering what the big deal is. In particular, it can be difficult to appreciate just how shocking it was in 1926 to have the killer of The Murder of Roger Ackroyd turn out to be the first-person narrator.
• The Untwist:
  • Seen in the first Poirot book, The Mysterious Affair At Styles, in which the first person suspected to be guilty of the murder actually turns out to be guilty of the murder. Comes with heavy lampshading in the novel itself.
  • This occurs in several other novels as well. One example is The Hollow, in which a man is found shot to death with his wife standing over him holding a gun. And the wife was indeed the killer.
• Values Dissonance: Many, many times. Most famously, the controversy over the title for And Then There Were None. Also a fair bit of casual anti-Semitism in the pre-WWII stories. To Christie's credit she personally edited out those pieces after the War.
  • Not to mention the "hooray for the upper-class" air that pervades the Poirot series. And Poirot's thoughts on race (the murder was done with a knife, clearly the work of an Italian or Spaniard due to the passionate nature of the stabbing!) are embarrassing to read.
• Why Would Anyone Take Him Back?: In Taken at the Flood, the main heroine, Lynn, ends up with Rowley, a character who was seriously trying to strangle her at one point, because Lynn, apparently, loves danger and risks. Yeah.
• The Woobie:
  • Alexander Bonaparte Cust in The ABC Murders.
  • Gladys in A Pocket Full of Rye