I saw it 4 times, so yeah I liked it.
Preproduction has already started on the next one and it'll be out in 2006. I've read that they're doing parts 2 and 3 back to back, so expect plenty of Sin City over the next 2-3 years. I just hope all of the same actors return to their respecitive roles given there are plenty of reappearances.
There's an extended version coming to DVD but it won't be the initial one in Sept.