Ah, realistically I should be giving this two stars. But I can't help myself, so three stars it is.
I really don't have much to say. It was enjoyable, and very well crafted (that's Alan Moore for you), but it was still lacking.
Moore did a good job not making this seem like anarchist propaganda, though some people seem to see it that way, it's not even supporting anarchy.
A few problems I had was, first off, the characters. They were all boring. V was the most interesting and he's not even a character! Moore specifically tried to make V appear as an idea rather than an individual. Which he pretty much succeeded in, but yet he is still the most interesting, not only as an idea, but as a character.
The rest of the character lot was filled with boring and unmemorable faces. Most of the time I couldn't even follow the characters and sometimes got confused who was who.
The plot was stupid and pointless, the fictional universe had numerous flaws. The book had its moments but was generally quite dull and muddy (like the art work).
One more plus was the use of music. Each song that is played had to do with what is going on in the book. Like when V references Sympathy for the Devil when confronting the Bishop. The devil comes in many guises, he is the bishop and his pedophilia, he is Norsefire for their genocide and oppression, and of course he is even V himself.
Or when Tchaikovsky's The 1812 Oveture was playing as V blew up Jordon Tower and the Old Post Building, the explosions surely were substitutes for the cannons that are traditionally heard in the piece's crescendo.
Even the extremely well crafted Velvet Underground reference (which was my favorite panel in the book) holds greater meaning. If there is anyone who has a keen taste in music, it's Alan Moore. Devo in Watchmen and The Velvet Underground in V for Vendetta.
All in all I don't think the book is truly deserving of a three, maybe more like a 2.5, but ca n'a pas d'importance.
EDIT: Bumped it down to two. I know, I know, I'm an idiot who can't settle on a rating, but two just seems better fitted.