12 Angry Men. My Dinner with Andre. Steve Jobs (a stretch, but much more a play than a movie).
There's some play adaptations which have few characters and mostly dialogue: Carnage, Who's Afraid of Virginia Woolf, Glengarry Glen Ross
Linklater's "Before" trilogy is also heavily dialogue-based, but the there are multiple locations.
"How About Adolf?" (2018) [0].
"Perfect Strangers" (2017) [1].
El método (2005) is a really good take on corporate/personal dynamics.
The Big Kahuna (1999) ("the majority of the film takes place in a single hotel room, and nearly every single line of dialogue is spoken by one of the three actors.")
Re:Age Reduction Breakthrough?
by abiogenesis on Monday May 11, 2020 @07:49PM
(#23148829)
Not exactly a dinner party movie, but Sleuth (1972 and also the 2007 remake) is a good one.
I love those kinds of movies. It's a Disaster (2012) is a good watch.
Exam (2009) is another good single-room film.
Some of my favories: