Sin City is highly overrated => 3/10.

Rating: Null/10 (6 April 2005)

I found this movie extremely disappointing. If you have any doubts about seeing it, have another movie option, or just plain have something better to do, then I recommend passing on this movie. Perhaps rent the DVD in a few months if you're still curious.
One of the factors that influenced my choosing to see this movie was its high rating here on IMDb - anything with over an 8/10 is usually reasonably good (or at least not terrible)... until now. If you're a teenage boy with a short attention span (or one at heart), then you'll *love* this movie, and will likely become a rabid fan attempting to convert (and/or purge) the nonbelievers (look around this message board). Otherwise you will probably leave the theater decidedly unimpressed.
And for the record, I loved Kill Bill and Pulp Fiction; Sin City attempts to create a kind of Tarantino-esk film noir artistry, but just ends up coming across like the cut scenes in a bad video game. For such an 'original' movie, it was surprisingly formulaic.