I just saw Scott Pilgrim vs. the World and loved it. As a fan of the comic since the first book dropped 6 years ago I couldn't be happier with how the film adaptation came out. Even with all the liberties taken in the film, especially in a few of the fight scenes, I thought it was excellent. In fact you might say that it was because of the liberties that were taken that I liked the film so much. Allow me to explain:
Watchmen was a comic book work held dear by many and though it had been spoken of in the past, until Zack Snyder came along, no attempt to adapt it for the screen had ever succeeded. Such adaptations are often met with apprehension by fans of the original work and for good reason. People have an attachment to Watchmen and other non-mainstream properties and if that property is going to be brought to a larger audience, they want it to retain it's integrity. They don't want the thing they're passionate about sullied in the eyes of the masses by an inferior adaptation. With Watchmen it was a simple choice, either do it as faithfully as possible or don't do it at all. The fans were too rabid, the backlash would have been devastating. An adaptation wouldn't do, only a big screen translation.
Watchmen the film recreated the comic with at least 90% accuracy and while others were thrilled at the chance to see their beloved story so faithfully recreated in a new medium, I left the theater with really no opinion at all other than that it was a very faithful translation. Scott Pilgrim on the other hand, while it had faithfully translated scenes, was more of an adaptation and I was much more excited after having seen it. The difference for me between an adaptation and a translation is that while a translation is attempting to faithfully recreate the language of one medium in another medium while losing as little fidelity as possible, an adaptation takes liberties in order to do things in the destination medium that cannot be done in the source medium thus making both valid. Watchmen the book is a great book while Watchmen the movie is a great translation of that book. Scott Pilgrim the book is a great book while Scott Pilgrim the movie is a great movie based on that book. See what I'm getting at?
Watchmen the movie didn't take any real liberties with the source material, it didn't do anything in order to make the story a better movie, it just translated what was already there onto the screen. Honestly there was no choice. Watchmen was too big and too tight a narrative to take liberties with. The choice was make the movie or don't and having seen the movie I don't see the point, I'd rather read the book. It's the same for me with Sin City or The Road. Scott Pilgrim remains very faithful not only in theme but in characters, setting, and even certain scenes, but it takes liberties that make it a better movie and that makes the movie not just an image of the source material, but an entity in and of itself.
There's a bunch of material not present in the Scott Pilgrim movie due both to time and pacing concerns, but you don't miss it and its absence is to be expected anyway. Certain liberties that were taken however (like the completely changed fights with the twins and Gideon and certain smaller liberties taken with other scenes) did nothing to detract from the intent of the source material and helped make the film autonomous. If you like the Scott Pilgrim movie you'll like the comics and if you like the comics you'll like the movie. The best part is that there are different things to like about both and that makes them both valid. Liking either the book or the movie can be completely autonomous, but if you like both you're not just getting one original product and another shadow of that product, you're getting two complete things.
I don't need the Hollywood or the mainstream or whoever to like comics. I don't need comics made into movies to show "them" that we're a valid medium. It's not going to work anyway. If you're going to make a movie of a comic and you can only make a Watchmen-style translation then just don't do it, you're not adding anything to it. If you have a property like Scott Pilgrim and you can make a movie that is as valid as a movie as the comic is valid as a comic then be my guest, I look forward to it.