And speaking of subtle, atmospheric horror:
The Changeling (1980)
George C. Scott is a composer who after the death of his wife and daughter in an auto accident, moves to Seattle to "get his shit together", as it were. He manages to score a lease on an old mansion that's currently owned by the local historical society. Needless to say, the place is haunted. But not "possessed" (e.g. Poltergeist, The Amityville Horror); no, there's just a lot of odd things going on. The running faucets. The loud banging at the same time each morning. The ball bouncing down the stairs. The fact that no one really wants to talk about the place's history....
It's a haunted house movie for grown-ups. Not only are there no young people in the cast, all the actors are seasoned, mature professionals. And there's no gore - not even any real blood, even including the car accident(s) - or cheap jump scares. Just a spooky tale about a spirit that cannot rest until it's been avenged (which adds a very nice mystery to the story).