“Best” being the interiors where the design is critical to the movie, where the interior is almost another character.
Holy schmoley, I just watched Fanny and Alexander. The Ekdahl house was welcoming and warm, the Bishop’s house was coldhearted and dead, and Isak’s house was mysterious and fantastical. The movie almost didn’t need actors to tell the story.
IMHO some other spectacular and resonant interiors are the house in The Others and the hotel in Kubrick’s version of The Shining.
What interior settings have added greatly to your enjoyment and understanding of a movie? Or a TV show – I can’t think of any right off, but there must have been some on TV.