YMMV / Sisters (1973)

• Awesome Music: Bernard Herrmann, relishing a chance to do a Hitchcock-esque film again, rose to the occasion with a score that recalls his work on Psycho and Vertigo, but adds other memorable touches like a Theremin. The murder motif here might be even creepier than the "Psycho" Strings themselves.
• Crosses the Line Twice: The idea of the African Room restaurant. It looks very insensitive even for its days, but giving a dinner for two there as a game show prize to an African-American man is ridiculously disrespectful. It's also a case of Aluminum Christmas Trees; it was a real New York restaurant that first opened during the "exotica" craze of The '50s, with performances by genuine African and Caribbean music acts.
• Growing the Beard: While he revered Alfred Hitchcock, Brian De Palma first gained notice with satirical comedies in the vein of one of his other idols, Jean-Luc Godard. After the failure of Get to Know Your Rabbit, an attempt to do a more mainstream version of those countercultural films, he decided to revisit the Psychological Thriller genre, and figured out how to take the Black Comedy and unorthodox techniques of the earlier films, and blend them with homages to Hitchcock and other filmmakers. Sisters was critically acclaimed and did decent business on a low budget, and gave De Palma a new career path that would lead to greater success.
• Harsher in Hindsight: Danielle being put in a mental institution, after Margot Kidder suffered a similar fate during her infamous struggle with bipolar disorder in The '90s.
• I Knew It!: It's not hard to figure out that Dominique is actually Danielle's Split Personality, since the character is depicted in an ambiguous and slightly confusing way to begin with. But you really have to pay close attention to catch on that they were separated Conjoined Twins and Emil Breton was the doctor who performed the surgery before The Reveal.
• One-Scene Wonder: Several memorable people pop in-and-out of the film, but none more so than Catherine Gaffigan as Arlene, the germophobic patient at the Lynton Clinic. Some of her lines have even undergone Memetic Mutation.
  That's how I got so sick...SOMEONE CALLED ME ON THE TELEPHONE!!!
• Retroactive Recognition: Future Oscar winner Olympia Dukakis as Louise, the bakery worker.
• Rewatch Bonus:
  • Danielle telling Phillip "I don't bite, you know" when she talks to him after the game show taping is definitely Harsher in Hindsight when you know what happens to him. She doesn't bite, but she stabs.
  • Dr. Breton becomes slightly more sympathetic when you know his exact relationship with Danielle: he's stalking her out of love and concern, since he knows that "Dominique" has been causing trouble for her.
  • On rewatch, since you know the plot twists, you can appreciate the truly hilarious moments of the film more, like the Running Gag of Grace making things worse for herself by constantly picking up the Idiot Ball.
• The Woobie:
  • Danielle is played by Margot Kidder at her most appealing and her most vulnerable, so you really feel sorry for her once you learn just how messed up she is.
  • Poor Phillip, a genuinely good-hearted guy who gets lured into an absolutely horrific situation.
  • Grace moves closer to Jerkass Woobie territory with her sometimes abrasive personality, but it's still painful to see her get victimized in so many different ways as the story goes on.