The Social Network rides into town on the back of the biggest buzz of any film of 2010. The only film greeted with more anticipation by more people this year has been Toy Story 3, and even that was less about the movie itself than about its predecessors. So it's a bit of a nice coincidence that The Social Network should end up being the best film released in America since that same Toy Story 3: it is quite pleasant to have anticipation rewarded, something that hasn't happened nearly often enough with this year's films.

I must imagine you know that the film is about the founding of the wildly popular Facebook, one of the cornerstones of the modern culture of the internet: how in 2003, a socially awkward Harvard undergraduate named Mark Zuckerberg (Jesse Eisenberg) took the first steps on a road that let, in about two years, to an amount of money almost unthinkable for what, in 2010, remains at best a marginally profitable website. And then came the lawsuits: from Facebook's co-founder and Zuckerberg's ex-best friend, Eduardo Saverin (Andrew Garfield), and another from 6'5" Olympic-class rowers, and all-around Aryan demigods, the twins Cameron and Tyler Winklevoss (both played by Armie Hammer), who claim to have planted the idea for a Harvard-exclusive social networking site in Zuckerberg's head to begin with (recall, as weird as it sounds, that for the first couple of years of its life, you had to have a .edu e-mail address - and at the very start, one from a particular and mostly elite list of universities - to get a Facebook account).

It looked for a while that The Social Network was going to be some kind of generational narrative about what life in the Internet Age looked like - it is not. It is only marginally a story about the internet or Facebook at all, and writer Aaron Sorkin's contention that a similar movie could be made about the inventor of a really nice toaster is, basically, correct (with significant qualifications). Assuming that this toaster was invented by a painfully asocial genius with absolutely no ability to filter his ego.

For despite all the other things that the movie is - and it is a great many things: a giddy comedy, a surgically precise dissection of the social mores of elite institutions, a marvelous piece of top-shelf cinematic craftsmanship, a consideration of how communication works in a plugged-in world, a cornucopia of dense techie shop talk that suggests what Star Trek: The Next Generation might have looked like with Sorkin as a staff writer - The Social Network is the story of Mark Zuckerberg. Or better, maybe, to say, "Mark Zuckerberg" - one of the most surprising (and gratifying) aspects of the film is how much it plays like fiction, even despite the millions of people who use Facebook every day. For all that it is based on events which happened, at most, seven years prior to its release, The Social Network never seems to claim for itself the mantle of "a true story"; for Sorkin and director David Fincher, what they can say about human behavior c. 2005 using a largely artistic construct that maps onto the real-life Zuckerberg is the only real concern.

This is true even within the film. "That's not what happened" is the first thing that comes out of Movie-Zuckerberg's mouth in the "real" part of the film, which alternates between the depositions after the fact, and the history of Facebook being recounted at those depositions. Maybe it isn't what happened; maybe it is. But every word of it is presented as being the testimony of Zuckerberg's accusers, and never of Zuckerberg himself. Though, to be fair, the defendant's responses are enough to convince him that the central tenet of all the accusations - he's pretty much an asshole - is fundamentally accurate.

At any rate, The Social Network is the story of a young man with a crippling inability to deal with other human beings - a driving theme present in virtually every scene, beginning with the already-legendary opening in which Zuckerberg gets dumped by his girlfriend Erica (Rooney Mara) at the end of a five-minute festival of the most swirling kind of Sorkin dialogue - and his apparent indifference to that fact. Apparent, I say, because the irony of the story is that virtually every act that Zuckerberg performs in some way manifests his desire to be more socially functional, which he achieves by changing the way everyone else exists in society (this, at least, seems to be a genuine extension of Real Life Zuckerberg, with his skin-crawling, offhand dismissal of the very notion of "privacy" in the online world). Zuckerberg wants to be a good, beloved guy - he's just too broken to know how to go about doing that (the final scene of the movie plays with this idea both for pathos and sarcasm, in the exact same instant).

That's not even scratching the surface of a movie both incredibly rich with ideas, and extremely generous about letting itself be read. But that's what happens when you have such gifted filmmakers on board. Fincher has fully redeemed himself from the abortive The Curious Case of Benjamin Button, and then some: though I still marginally prefer Zodiac for its grandeur and breathtaking Harris Savides images, I would otherwise not hesitate in proclaiming The Social Network the most crazily accomplished of the director's films. Unsurprisingly for such an exacting visual artist, it is entirely full of immaculate scenes in which every detail of the frame has been ordered just so: never in a splashy, "look at me directing!" way; but the edges of The Social Network are alive and breathing in a way hardly typical of even very good movies. This is the kind of fussy perfection that comes from a director who likes to shoot dozens of takes; the kind of a director exactly opposed to all that Sorkin's writing ordinarily stands for, and yet (with apologies to Thomas Schlamme, whose work in that man's three television series is some of the most revolutionary and important TV directing in history), Sorkin has never been as well-served by a director as Fincher. The precision of the film's mise en scène gives a jolt of intensity to the hyper-articulate writing that energising and wonderful to behold.

Lest I be accused of making this the Aaron & David show: everyone involved contributes something great, with the clipped editing by Kirk Baxter and Angus Wall doing more than anyone including the director himself to create and maintain the exacting rhythm which makes a 121-minute film skip by like a summer afternoon, which makes a sharp comedy crackle along with the driving force of a political thriller. It's subtly and beautifully shot by Jeff Cronenweth, scored with wildly unexpected verve by Trent Reznor and Atticus Ross - the deeply unconventional soundtrack could not possibly fit the film any better, perfectly complimenting the snotty tone of the writing - and even the tiniest details of costume and set design add much to our sense of the characters. As for the actors behind those characters, they're all pretty great: yes, Justin Timberlake steals the show as a devilish Sean "Napster" Parker, Hammer's digitally-aided performance as twins is a marvelous career-making comic turn, Garfield is deliriously on-form. The grand central performance by Eisenberg trumps them all. Where has this actor been all these years? Surely this is not the lazy Michael Cera clone of Adventureland, up there projecting a quivering mask of short-tempered egotism, with eyes that are always thinking a hell of a lot more than the rest of his body tells, though God knows what they're thinking. It is, simply put, one of the best performances of the year despite being two things that usually can't translate into great acting: almost entirely reactive, and utterly inscrutable. It is through Eisenberg's tremendous embodiment of a thoughtless, cocksure genius-prick that the film's creation of its Zuckerberg, its avatar of all that is broken about 21st Century humanity, all that humanity strives to be, and all that humanity is willing to settle for when it looks in the mirror, is so compelling and complete.

There are just enough flaws knocking about here and there that I can't quite follow the party line to "instant-masterpiece" status: for starters, the framing narrative is baldly functional, with one character in particular existing only to express the movie's concluding message, and saved only because she is played to absolute perfection by Rashida Jones - and yes, such clunky use of the film's most prominent female character is a harsh reminder that we're in Sorkin Country, and that Zuckerberg's knee-jerk sexism that opens and in some ways drives the movie is unique among the writer's works only in that the character is actively punished for it. Other viewers will, I'm sure, find other complaints - a film with such immaculate visual storytelling can still have the occasional misjudged frame or awkward CGI shot (it is Fincher) where the effects are too transparent - the fog coming from the actors' mouths in a winter scene is distractingly cheap. But on the other hand, the immaculate storytelling is there nonetheless, and even if it's not the best film of the year so far, The Social Network is way up near the top.