I've always had a sort of liking for the concept where a character is sort of reborn due to mental trauma. Someone is pushed to the brink... and they come back, all the more different, stronger, and dangerous for it.
V for Vendetta perhaps epitomizes this concept to a degree, but that's only more or less the synopsis that we're given in the marketing. It epitomizes some other concepts even more... namely the "revolution" and "political uprising" concepts, plus another one which I'll get to later.
We are introduced to the character who only goes by the name V (played awesomely by Hugo Weaving), and wears a Guy Fawkes mask. He makes his entrance by saving a reporter named Evey from the secret police. And then he blows up a building. And promises to blow up Parliament on the 5th of November, bringing about Guy Fawkes's plot to life.
Yup, sounds pretty simple from the surface. Psychotic terrorist goes and blows up things and throws knives at people. The main difference is that this is the *protagonist* we're talking about. Is he the good guy? A bad guy? An anti-hero or anti-villain? That is ultimately left for the audience to decide and formulate their own opinion upon, as are many other things.
As it turns out, though, things are way more complex than we thought. V has a secret past that ultimately made him what he is, and he's all the more dangerous for it. But this is all part of another concept that is used to near perfection in this film: the domino effect.
The domino effect is used amazingly in this film. It's all revealed over time, but everything in this film is part of a chain of events. Cause and effect. Without giving too much away, V and another character in this film are both saved by the hope of another; a ghostly figure of sorts. The atrocities committed by the government ultimately lead directly to the molding of V; which ultimately leads to his vendetta. It's an even more complex chain of effects/domino effect than that, but I won't say anymore for the sake of avoiding spoilers.
V for Vendetta isn't really a story about the characters within it. If it were, one would probably be left with more of a bad taste in their mouth. It's more about the chain of events that leads to the revolution. It's more about the idea than it is the character that's leading the charge. Yes, V's a very interesting character, albeit a flawed one; but what he is is only brought about by what was forced upon him.
Things aren't perfect within this film. There's a couple of scenes we probably could've done without, even if they were perhaps necessary for the film's ideas and symbolism. Much like other things in this film, though, different people will react differently to it. People will react differently to the film overall. Some won't like it much (especially if they disagree with its political uprising statements), and others will love it.
Essentially, what we expect isn't what we get. We kind of expect to watch a guy wearing a sort of goofy mask rampaging around England with knives and ammunition. Yeah, we get a bit of that (there is a particularly cool scene near the end with said throwing knives), but again, this movie is more about the chain of events. The domino effect. The idea. And it employs said tactics to near perfection.