Look it up:
Noir doesn't get any blacker than this, nor any better. Sin City is a series of four stories, linked by a few common characters, and by the seedy location of Sin City itself. The stories cover revenge, justice, and the struggle of the downtrodden at their most basic and brutal. Life is cheap, violence is ubiquitous, but the good guys (or at least, the less bad guys) still fight for the ones they love. Told in an arresting, partially colourised, high-constrast black-and-white visual style with voice-over narration, it really is a film that has to be seen to be believed.