1990. Dir., Whit Stillman (also known for The Last Days of Disco
The film is about upper-class college kids hanging out during New York's season of debutante balls. Scene by scene, the film is a long series of conversations, many of which focus on the definition of bourgeoisie--one character, with a particular fear that the New York socialite way of life will collapse, is obsesses over the idea that there is an "urban haute bourgeoisie."
Stillman does little with the camera and there are no shots in the film that one would call beautiful. But the film demonstrates that complex dialogue can be filmed.
Here is part of the scene where the main character first mingles with the "Sally Fowler Rat Pack" (SFRP):http://www.youtube.com/watch?v=3plmkRy_k5o