I'm divided about this movie, really.
On the one hand, i have to agree with all of you here (except Richard), that it's a great movie. It IS great, technically perfect, cool soundtrack, cool characters, everything so dead cool. It's very entertaining and gripping.
But on the other hand, it's also very violent. I think a good movie needs no violence, even when it's about violence. Sin City is not only violent in it's pictures, but also in the attitude delivered. The "good" guys like Marv, Dwight and Hartigan run around killing people as if it was the most normal thing. Marv even tortures his victims. I didn't like that part one bit. To me, it would have been enough if he just killed them
Overall i'd say it's well worth seeing, but you shouldn't leave your critical faculties at home, as you can easily be blinded by the flashing appearance of the movie.
There are some really cool lines in it, though
"Here's a trace!"
The best part was the speech of the senator in front of Hartigans bed. The part about power and lies.
"If you can convince the people that their own feelings are wrong, the word will be your oyster!" (i translated what i remembered of the German translation, so probably it's very far from the original....

)
Hartigans heroic efforts to save the girl are also very cool, and inspiring
Okay, just my thoughts
D.