YMMV / Gaslight

• Adaptation Displacement: The 1944 film is better known than the play and the UK film version it's based on. The studio tried to enforce this by having all prints of the previous version destroyed (so, ironically, they were trying to gaslight people out of remembering that the UK version existed). Ironically the remake had the title 'The Murder in Thornton Square' for the UK release to avoid confusion - but of course the original title is used these days.
  • Meta-example. These days, the term "gaslighting" itself, and what it means, is more well-known than the movie that named it.
• Catharsis Factor: The ending, when Paula furiously throws Gregory's abusive gaslighting techniques back in his face before calling in Brian to take him away.
• Common Knowledge: This is one of the great moments of Alfred Hitchcock's career... except, it was directed by George Cukor. It's easy to see why people would think it's a Hitchcock film, though: it's a classic Psychological Thriller, with a One-Word Title, and frequent Hitchcock leads Ingrid Bergman and Joseph Cotten are in it. He did direct a similar film called Suspicion, which has the opposite climax where the man turns out not to be a murderer.
• Ensemble Dark Horse: Angela Lansbury as Nancy, the Cockney maid, made enough of an impression to get an Oscar nomination, even though she's, at best, the sixth-most important character in the story. The impressive thing is that she had no acting training, and was just a natural in front of the camera.
• Hilarious in Hindsight:
  • Angela Lansbury playing an oblivious pawn (and Red Herring) in a murder mystery first becomes amusing as of Death on the Nile - where she's a crime novelist who unsuccessfully attempts to solve a murder mystery. And then of course with her famous series Murder, She Wrote, which is about her solving mysteries. Plus, she sings about balloons.
  • Joseph Cotton played a killer himself in Shadow of a Doubt, and he'd be on the other side of a Gaslighting plot in Hush... Hush, Sweet Charlotte.
• It Was His Sled: An odd case where the original play and its earlier film adaptation are clear from the start that the husband is a jerk who's deliberately manipulating his wife, but the more famous film tries to make it a twist with Gregory able to put on a believable front as a loving, sympathetic husband. Of course, the fact that the very title has become an official term for this kind of abuse gives things away these days.
• Memetic Mutation: The term "gaslighting" has become a byword for Mind Rape tactics used by domestic abusers. Ironically, tampering with the lights was the only aspect of Gregory's abuse he did unintentionally.
• Paranoia Fuel: It's written into the film! Gregory has Paula doubting her own sanity so easily, which can be very alarming at how effectively he accomplishes it.
• Retroactive Recognition: A 17 year old Angela Lansbury makes her film debut as Paula's maid.
• Signature Scene: Paula confronting Gregory and giving him "The Reason You Suck" Speech - while Trolling him with her apparent madness. It's considered one of the finest moments of Ingrid Bergman's career.
• The Un-Twist: Gregory being the letter's sender or his accomplice and Alice Alquist's murderer becomes painfully obvious once the letter is brought up, thanks to his bizarre and violent reaction to Laura finding it.
• Values Resonance: The film examines psychological abuse that can happen in marriages and relationships, and Paula comes out the other end able to confront her abuser and not let what he did to her rule her life.
• The Woobie: As Paula's constant undermining by Gregory takes its toll, it's hard not to want to give her a reassuring hug.
  Paula: You mean we're not going to the theatre?