No need for spoilers in this review.

Filming : 10/10
Simply breathtaking, the B/W creates a dark atmosphere and the highlighted elements (colored) are magnificent.
As incredible as it may sound, the movie looks actually very colored, probably because those elements are key elements in the different stories (or simply look better that way ^.^).
The scenes are often shot under many different points of view, which makes each scene important.
Needless to say, the filming is excellent.

Acting : 7/10
There are a lot of hot shots in this movie, they do their job very well, may they be heroes or villains. I was especially surprised by Mickey Rourke's character, my personal favorite, who interprets incredibly the lone wolf fighting fiercely for his lady. Second was Clive Owen, who shows an incomparable embodiment of his character, better that in any film I saw him play in.

Plot(s) : 9/10
The movie consists in 4 different stories, they are all sort of linked together, and we see every facet of Sin City, who shows us the eternal fight between good and evil, just like any comic. But this time the good guys aren't so nice, they aren't your average neighborhood cop, they're more than simple heroes, they're super-heroes !

Overall impression : 9/10
Congratulations to Rodriguez and Miller.
Truly the best attempt I have seen to adapt a comic series on the big screen, Sin City had me glued to my seat from the very beginning. All is black and red, a disgusting mixture of every kind of brutality you can imagine. And more.