First off, some kudos: whoever created The Rules of the Game trailer for Janus Films deserves an Oscar for capturing in a minute and half the greatness of this film. Simply put, Rules deserves the highest accolades according to the BlueStar criteria. As shown in the clip, it influenced many of the great directors from Robert Altman to Francois Truffaut to Alain Resnais, and we can see elements of Rules (La Regle du Jeu) in countless films made since 1939.
The closest modern film comparison would be Robert Altman's Gosford Park (2001); both are character intensive films set largely in the country home of a wealthy landowner. Like Gosford, this film is as much about what is not being said as what is said. Both films' fascination lies in examining both the lives of the rich and the poor servants as well as the interplay between the two. In this scene, Renoir shows that the drama behind the scenes is often far more intriguing than the play being performed for the audience; Gosford Park hits this same note, focusing on the high-low dynamics: showing action upstairs where the rich live and juxtaposing this against the actions in the basement, where the servants dwell and prepare the food.
Finally, the history behind the making of Rules is covered admirably in the DVD extras. This includes the story of how the original print was lost during World War II and how when it was re-released in the 1950s a handful of different cuts were made at the end of the film, thereby changing the entire message and tone of the ending.
The Rules of the Game is like a complex wine which has aged amazingly over time. Whether or not you're a wine connoisseur, you will thoroughly enjoy it from beginning to end.