V for Vendetta is a pretty good movie, but it's a better comic. Like always, I think the movie would be improved by staying truer to its source.
The only example I feel safe about giving without spoiling anything is the shameless political orientation of the movie. Apparently, the Wachowski brothers don't like the Bush administration, and feel that someone else's story is the best venue to vent their displeasure. If you want to attack someone, make your own story.