Little Shop of Horrors
Seymour Krelborn is a nerdy orphan working at Mushnik's; a flower shop in urban Skid Row. He harbors a crush on fellow co-worker, Audrey Fulquard, and is berated by Mr. Mushnik daily. One day, Seymour finds a very mysterious unidentified plant which he calls Audrey II. The plant seems to have a craving for blood and soon begins to sing for it’s supper.
Horror is meaningful and drives key elements (Audrey II's blood-fueled growth, killings, grotesque imagery, and existential dread), but the film is also a musical comedy with romance and satire. Removing horror would alter the experience, yet the movie is not solely a horror film.
Movies with a similar horror experience.