+8
It's a genre that I adore. It doesn't have to be too strict in my book, but, aside from -obviously- 12 Angry Men :
Cuisine et Dépendances is my favorite. It's, as often with these things, the adaptation of a theatrical play, but they just added a short intro in a supermarket, and the rest takes place entirely in a kitchen. Imagine Polanski's Carnage but way, way more subtle, complex and deep. Because Jaoui and Bacri were, sorry to say, miles above Yasmina Reza (whom I find way overrated, especially when it comes to endings).
Das Boot has a few scenes in a harbor brothel or on a supply ship, but still, it's as one-location as the ultimate submarine movie can be. Okay, granted, it's a location that moves around, is it cheating ?
I do also classify The Thing as such, because the isolated Antarctica station does play a lot on that sort of claustrophobia. Being locked in with people you distrust (and might ingest you any time).
By the same standard : The Shining, although the overlook is so wide and its topology so wonky it could be numerous places just as well.
Also Sleuth. I don't remember the details of that movie, only the love I had for it.
Scare Me is a marvellous little movie, just made of conversations (and hilarious sound effects) in a remote cabin.
And I have a solid fondness for Dead Calm. Three characters, one boat (and a half), one psycho. And that weird, weird breathy soundtrack...
I'd also give some honorable mentions to :
All is Lost. A bit like Dead Calm, minus two characters. Open Water. A bit like Dead Calm or All is Lost, but without the boat under the feet. And the second half of Jaws, if I may. The whole first half prevents the movie to be classified as one-location, but damn, does the second half play it well. My Dinner with Andre is lovely, and gives you the impression of having travelled way farther than that restaurant. Garde ŕ vue is a cool film, a lot of tension between the suspect and the cop who is drilling him in that room, but I wasn't too convinced by the ending. Evil Dead and its cabin had efficiently terrified me as a teen. And Murder by Death should count too, I guess, with its and-then-there-were-none kind of manor.
(For the record : Far far far, far far at the bottom of the list is Room 1408 because haha, hahahaha, hahaha.)