Good review by Nick Mamatas here. I can't improve on this comment.
V isn't really a man, the struggle in the film really isn't a political or economic struggle; it's an Idealistic one, and specifically a mystical one. Both Moore and the Wachowskis are interested primarily in the esoteric. V for Vendetta is actually a movie about initiation and manipulation of symbols to change consciousness and affect reality. You know, all the stuff you think of forty-five minutes after you bring home your first bong. But for all that, it's really a fun movie!
Blake's idealism is in there, and the ritual magic element. As Mamatas says 'Snakes eat their own tails yummy yum yum'. I am also happy to see the Benny Hill theme tune used for magical purposes :-)
A few more reviews I think you'd enjoy.
redstarrobot in several long comments to Mamatas' piece above, which add up to a fine review themselves.
coalescent in an f-locked post about lots of other stuff asks 'why every mainstream/newspaper critic seems to have panned V. I mean, it's not perfect, but all I've seen are one-star and two-star reviews. Why?'
My guess is that they have misunderstood the genre. To wonder (like Bradshaw in the Guardian) where V manufactured the masks for instance, shows a misunderstanding.
I didn't think Portman was crap, and she's extraordinarily pretty. Hugo Weaving was excellent. I thought his voice sounded a bit like Blackadder. John Hurt cannot fail to be good. The rest gave good grown-up performances.
And finally, I always judge a film to have been a success if it gives me dreams. This one did. Unfortunately rather horrifying dreams about a woman having her face eaten off.