One of the best comic book movies ever made, since it simply deconstructs the genre entirely. I liked it so much that i even changed my avatar to the Comedian.
General consensus, on the other hand, seems to be that it was overlong, plodding, style-taking-too-much-attention affair and demonstrates exactly why things that work in a comic book don't necessarily translate well to film.
I'm somewhere in the middle. I thought it was pretty dull at points but had it's moments. I was never a big fan of the comic either, though. Deconstructing something is fine, but if you're doing it in story format make it a story which has a decent payoff.