WILD APPLAUSESex and the City: Comedy-drama. Starring Sarah Jessica Parker, Cynthia Nixon, Kristin Davis, Kim Cattrall and Chris Noth. Directed by Michael Patrick King. (R. 145 minutes. At Bay Area theaters. For complete movie listings and show times, and to buy tickets for select theaters, go to sfgate.com/movies.)

Fans of "Sex and the City" will love the movie version.

Like the HBO series that gave birth to it, the movie is lots of fun, but it's no frivolous romp. The show's great ambition, always present, becomes even more pronounced in the movie - to document the emotional life and values of cosmopolitan women of a particular generation. It's as if its creators realized the series' significance over the course of its run, and that shift in the direction of importance - subtle, but definite - continues with this movie. Under the levity, there's a core seriousness about presenting these women's lives, one emphasized by the willingness of "Sex and the City" to grow and mature along with its characters.

Those who know these characters will, of course, pick up on nuances and associations that novices will miss. Yet even viewers coming in cold will appreciate "Sex and the City" as the best American movie about women so far this year, and probably the best that will be made this year. Indeed, at the rate Hollywood has been going, it may stand as the best women's movie until "Sex and the City II," if that ever comes along.

Coming in, Michael Patrick King, the movie's writer-director, had two difficult tasks: He had to introduce the characters to a new audience without irritating fans of the show, and he had to take a series that ended perfectly and un-end it, without seeming arbitrary.

He knocks off the first task easily, (re-)introducing the principals during a credits sequence narrated by the main character, Carrie Bradshaw (Sarah Jessica Parker), a best-selling author in New York City. There's Samantha Jones (Kim Cattrall), a successful publicist with a ravenous sexual appetite. There's Charlotte York (Kristin Davis), a gentle, princess-like wife and mother. And there's Miranda Hobbes (Cynthia Nixon), a lawyer and buttoned-down cynic, living in Brooklyn with her husband and son.

Un-ending the perfectly ended series takes a little more time. For the first 10 minutes or so, the movie hovers in place, emphasizing (and, for first-timers, introducing) the status quo. But then, the gears gradually move into place. Four years have passed. Carrie is still seeing "Mr. Big" - whose name is now revealed to be John James Preston (Chris Noth) - and the two decide to get married. This soon turns into plans for the fashion marriage of the century, with a guest list of 200 and a gown by Vivienne Westwood. But, of course, things can't happen too smoothly.

Meanwhile, Samantha is dissatisfied with her life in Los Angeles, even though she is still in love with her much-younger boyfriend, Smith (Jason Lewis), and Miranda and her impossibly sweet husband, Steve (David Eigenberg), are having marriage trouble. Though the laughs are frequent and the movie sparkles with glitz and fashion, an air of middle-aged disappointment is sometimes present, a realization of limits, of having to choose between imperfect options.

Suddenly, the women are most definitely in their 40s, and so their interaction with younger women is different, sometimes long-suffering, sometimes almost motherly. Carrie takes on a personal assistant (Jennifer Hudson, who's charming) and gives her sisterly advice, the hard-earned wisdom of 20 years in the New York trenches. The mature vibe shows that "Sex and the City" is elastic and capable of bringing in new elements of women's experience.

It clocks in at a hefty 145 minutes, but all that means is that it's like watching five episodes of the TV show in succession. Think of it not as a long movie but as the equivalent of an entire TV season muscled into one big megadose.

The allotment of screen time never seems obviously apportioned, but each actress gets a chance to shine. Charlotte's life is the most stable in this installment, but Davis has some of the best comic moments, and Cattrall shows a slight mellowing (and a definite deepening) in Samantha. As Miranda, Nixon is just brilliant, presenting her as someone increasingly locked into the patterns of her own personality, less hopeful and verging on bitterness. At the same time, underneath it, she's painfully sensitive.

Parker is lovely, alive to every nuance of feeling, her face the film's locus of meaning. Her lack of vanity is becoming. When Carrie gets beaten up emotionally, Parker allows herself to look beat up. In one's 40s, a person doesn't take an emotional beating and wake up the next morning looking as fresh as a 20-year-old. Parker lets us see Carrie's, and her own, true face.

There's something alive here. There's a feeling about this movie, that it's not some perfunctory cinematic appendix to a popular series, but the beginning of a whole new string of films. There's certainly no artistic reason "Sex and the City" can't be the women's equivalent of "Star Trek," with human emotion being the final frontier. Like outer space, that frontier is infinite.

-- Advisory: This film contains strong language and nudity.