If I had to describe this movie with one word, it would be "stylized," and not in a bad way.
The camerawork is fantastic to me. The way it moves through a scene to highlight different actors, the times it runs in for a dramatized close shot, the other times it slowly moves forward to build tension, and the quiet moments, when it sits still, introspectively.
There are many great uses of the camera, including the riff on Taxi Driver's "You talking to me" scene. A double was actually used for this scene with Cassel standing on the other side of an empty frame to make it appear as though he's looking at a mirror without having to worry about the camera being reflected.
The choice to go black-and-white really gives the film aesthetic appeal as well, which the camerawork just adds to. And there's also some really great music throughout the film.
The acting was great, and the characters are well developed. One of my favorite aspects of this film is how real each character feels. These kids are largely rough, uneducated, and unsympathetic, but they feel like people I have met in my lifetime. They feel like products of their environment, and their resentments and struggles feel real. Hubert of course comes off as the most sympathetic character, which makes the ending that much more tragic.
And what an ending! It's one of my favorite endings of all time, and I love the way the film is bookended with the story of the man falling off the skyscraper ("So far so good.") and the slow close ups of Said's face. The story is also wonderfully foreshadowed by the skyscraper frame, as the characters find themselves in tenser and tenser situations as the story moves forward.
To bring it back to the topic, I think this film is really compelling look at the lives of troubled, impoverished youth. it let's people really see their relationship with their society, their families, and the police. I think key scenes that reflect this are the rooftop scene, the scene with Hubert and his family, the art gallery scene, and of course the ending.
I never feel like there's any finger pointing in La Haine. It just feels like Kassovitz was trying to build empathy and understanding in the audience, while simultaneously giving a critical, as-real-as-possible look into the characters' lives and attitudes.