V For Vendetta

In 1983 (?) Alan Moore and David Lloyd put out V For Vendetta, a tale of vengeance, fascism, and what justice should mean, taking place in a 1998 London, England. 2006, the Wachowski Brothers bring you the movie, a tale of vengeance, fascism, and what freedom should mean, taking place in a 2015-2025 London, England.
The story is that of terrorism, freedom, anarchy, chaos, and those caught in between looking for what each means.
But as far as the comparrison between the two goes, we have to get more specific than my little summaries. Most comics to movies fall into one of two catagories: comics that have a solid beginning, middle, end (often a comic that's found in graphic novel format); or a comic that tries (often in vain) to sum up 30 to 70 years of story in tight little 2 to 3 hour movie. This should be the former, but instead presents a different interpritation of Moore and Lloyd's work.
So instead of the standard good, bad, and ugly statements (which will be present anyway), I'm going to give this one a little extra attention that it rightfully deserves. With that I will compare and contrast the stories, the events, and the players.

Codename "V": his origin and appearance remain the same, but his differences are subtler. For one thing in the comic, despite a few different tricks up his sleeve, his greatest strength is his mind. Sure, he's fast and strong enough to kill with his bare hands, but he's a thinker, a plotter. The movie he almost seems superhuman, able to substain a whole hail of bullets and keep on coming (the comic he's done in by 4). The movie he uses his knives in full, an expert, able to kill dozens of men in a instant. Not so much in the comic. And finally, his talking is far more straight forward in the movie.

Evey Hammod: First off, her age. Movie: 20's; comic: 16. In the comic she comes to V's attention as she is able to be raped and murdered by Fingerman, all because she (for her first attempt) picked the wrong guy to whore herself to, litterally. She's a teenage factory worker trying to earn money as a whore. Movie, she works at the TV station, and her crime is missing curfue (punishable by gang rape). She's far more naive in the comic, and stays with V because she sees him a father figure and a protector; while the movie she is his captive. She's a stronger person in the movie, someone who agrees to help V not because she owes it to him, but rather it is an attempt to gain freedom. And in the end she, in the comic, is V's successorm taking up the guise, the mantle, the whole nine. Movie, she is merely the one to help guide London to the next stage of revelution.
Plus the movie gives her a brother, though he dies from a nasty virus.

Finch: Physically there are obvious differences (age, hair, stature), but much is in the actions and backstory. For starters in the comic he had a romantic connection to Delia, the coroner. Next, he is actually the one to fatally wound V, not a mob of Fingermen/police. Then there's the acid trip he takes to help think like V (which is how he finds V in the subway). Movie, while lacking these, puts him as a larger player (which is a good thing)

Dascombe: The man in charge of media, the big difference is in the movie he actually survives, while the comic he's the man blasted while bound and wearing the mask. Past that, he (in comic) is a far creepier individual than we would find in the movie.

Gordon: Biggest difference of all characters, the movie portrays him as the (secretly gay) host of England's most popular show, who is brazen enough to mock the established power. He is the defier of the powers that be, and dies because of it. He takes Evey in because he knows about keeping secrets. In the comic, however, he is a cop who actually falls for Evey after taking her in like a stray dog. He exposes her to part of the secret underbelly of the police, but dies because he crossed the wrong blokes.

Chancellor/Leader: These are almost a night and day of characters, despite they both filling the same role. The Chancellor is the stern, goateed man who rules England with an iron fist. Always angry, he is the face of the Party, the man to fear. He dies because of betrayal, sacrificed in the name of capturing V. The comic's Leader however is more human yet more deprived. He is the all powerful head, but he is in love with Fate (a computer!). Never to know the touch of a woman, but in the end feels the bullet of one- killed by the Widow Almond. The Chancellor is far easier to hate.

Prothero: The Voice of Fate/England. In the comic he provides the Voice of Fate, the computer who all in England trust/fear. He collects dolls, and is driven mad after V burns them in the oven (as in concentration camp oven). The movie has him as the narscistic voice of London, the TV Personality who speaks for the Powers that Be. He is poisoned post shower.

Creedy: Of hand I don't recall if this his name in the movie, but the man in charge of Finger is the character. In the movie he is the scapegoat to the Chancellor, the man who's head will roll if V is not stopped. This leads him to betrayal, murdering the Chancellor execution style, and dieing by V's hands. The comic he is a pawn, someone with plans of taking the role of Leader by force and conspiracy, who in fact dies betrayed... by someone else's force and conspiracy.

The Story/Events: Much of the events follow the comic, but the sequence is different.
Comic goes: blow up Parliament, blow up the Old Bailey, blow up Jordon Tower (to knock out the Eyes and the Ears), go silent for 6 months, and finish off with White Hall.
Movie goes: blow up the Old Bailey, take over Jordon Tower, and finish off with Parliament.
While the order seems insignifant, the importance is stressed in each. The movie heavily stresses the Guy Fawkes connection, leaving Parliament as THE goal of choice. The symbol where it all culminates at.
The comic almost presents the Guy Fawkes connection as an afterthought, almost even a cover story for V to create Anarchy (in the UK!).
Then there's Fate, the super computer which (in the comic only) the government uses to help subjegate it's people. It controls the eyes, the ears, the voice of London. It keeps people in a police state, silent in their thoughts and opinions for fear of being the next to never return. The movie, they use surviallance as a tool, but not their only tool. The comic it is the key to maintaining what the Party so needs to have: order.
Then there is also the backdrop of the story. The comic is born of the Cold War. The bombs have been dropped and England prevailed. There is no more Europe, Africa, or America. Nuclear War Happened. Things became the way they did because supplies, food, the neccessities were in limited supply, order had been lost, and the Nordic Fire Party came in with their jackboots and changed that through fear, intimidation, paranoia, and sending away it's undesirables (much like the Nazi's did)
The movie however presented biological warfare as the cause. It wiped out the US as a superpower, and the Nordic Fire Party uses it to take power (yet more conspiracy is afoot!)... which is where V's origin comes to play.
Speaking of V's origin, the movie left one key thing: how the fire came to be that set him free.

The Good: Most of the key players are here, and they didn't alter V to the point of no return. Far from it, they altered him into more of a superhero (or is that supervillian?). Usually the alteration of the sequence of events would spell disaster, but here it makes the movie good (yet much more of a Hollywood thing)

The Bad: In modernizing they changed characters...in some cases completely. In the name of purity of the translation that is a bad thing, yet somehow more entertaining.

The Ugly: The loss of some characters: Almond, his wife/widow, Heyer and his (manipulating) wife, etc. In the comic they all play major factors in the events that follow. Taking them out takes a layer out of the movie, though their removal brings more focus onto V, Evey, and Finch. How players react, act, and meet their fate is altered because they were removed.

How Close to Perfect: 6/10 In some ways the story is completely different, in others exactly the same. But what could be expected when a movie is done almost 20 years later, especially when the source material is keyed to the times (Cold War fears were very real in the 80's; much as terrorism is today)? Changes are abound, and to make this movie much more significant and much more watchable other changes were called for. A call for Jusitce becomes a call for Freedom; the heart of the movie altered. The story became more action oriented yet more stream-lined.
Is it a good movie? Better than that, it's great and should be viewed by all who care. But is the movie a good translation? Not as much, but it's almost expected. The times have changed, and while the source material made sense and was topical in the 80's, new fears have taken our attention in this new era.
Rating this a "6" is not an insult; it's just a fact that things were altered and it is not the same story that Alan Moore wrote with David Lloyd. It's a great movie, and a great story... but it's a seperate being than the comic.