La dérobade (1979)

A young girl from a working-class family falls for a man before she discovers he is a vicious, sadistic pimp.

From memory: highly energized, violent and quite repulsive drama about prostitution on the verge to exploitation; disturbing and controversial, but Miou-Miou's performance is remarkable.

36 Quai des Orfèvres (2004)

In the underbelly of the Parisian criminal world, the police are frustrated by a gang committing a series of violent robberies, while two cops are seeking promotion, and the imminent departure of the Chief of Police sets the scene for them to compete for the vacant throne.

Excellent tough and very bleak policier exposes police corruption as just as terrifying as the criminal world.