Based on the best-selling novel by Lauren Weisberger, "The Devil Wears Prada" turns a sharp razor's edge to the stress-filled, nightmarish experience that is being a lowly assistant to a tyrannical fashion magazine editor-in-chief. It is not by accident, then, that Weisberger previously lived the part, acting as assistant for a year to Vogue's own editor-in-chief Anna Wintour. If the book is a thinly-disguised representation of Weisberger's own life or whether the plot details and characters are mostly fictional makes no marked difference; as a film adaptation, "The Devil Wears Prada" is the year's shrewdest comedy thus far. Funny and vastly entertaining, to be sure, the film is also bitingly satirical without straining toward caricaturizations and ultimately humbling in its sympathetic observations about people seduced into risking whatever it takes to excel in the competitive working world.

Freshly graduated from Northwestern University, aspiring NYC journalist Andy Sachs (Anne Hathaway) finds herself seeking and actually receiving a job as second assistant to top fashion magazine Runway's merciless editor-in-chief Miranda Priestly (Meryl Streep). Andy is an awkward match for the position—she dresses plainly, has no interest in or knowledge of the world of haute couture, and is considered heavyset despite being a trim size-6—but knows that working in the trenches of such a high-class publication for a year could earn her a writing job at the magazine of her choice.

This goal turns out to be easier said than done, as Andy's outside life—her relationships with live-in chef boyfriend Nate (Adrian Grenier), friends Lilly (Tracie Thoms) and Doug (Rich Sommer), and family—slowly but surely is monopolized by her professional obligations to the extraordinarily demanding and impersonal Miranda. Andy is having no fun working herself to the bone and getting zero thanks in return, but something unanticipated happens as the months tick by and her fashion sense improves: she becomes so caught up in making a good impression and answering to her boss' every whim that she starts to lose sight of the girl she once was.

"The Devil Wears Prada" was directed by David Frankel, a savvy, clear-eyed filmmaker who—no surprise—cut his teeth on episodes of such career-oriented television shows as "Sex and the City" and "Entourage." Guided immeasurably by an artfully intelligent and winsome screenplay by Aline Brosh McKenna (2004's "Laws of Attraction"), Frankel shows a true gift in discovering the quirky, painful, sometimes bitterly humorous truths that go on in an oppressive workplace. Although specific details and scenes might seem exaggerated to the common viewer who has not personally worked in the fashion industry, never for a second does the picture cross the boundary into far-fetchedness or off-puttingly broad stereotypes.

The characters are not streamlined to be good or bad, but are written as complex individuals who, even in the case of backbreaking ice queen Miranda and her by-the-book first assistant Emily (Emily Blunt), have the capability of throwing down their defenses and showing a touchingly human side not often revealed. As Miranda Priestly, Meryl Streep (2006's "A Prairie Home Companion") is frighteningly good, her award-worthy, tour de force performance a study in the power of subtlety and suggestion. Without ever raising her voice—actually, her slow, measured speech would suggest she's too cool and above everyone else to hardly bother speaking at all—Streep has fashioned an unforgettable character whose daunting, steely control of everyone around her masks a lonely person who has made peace with the choices and sacrifices she's made in her life. She may have sold her soul to get ahead, but her dignity remains intact. And, in the ways in which Miranda warms up to Andy throughout the film by a simple glance or line of dialogue that hasn't "thank" or "you" anywhere to be found is distinct and effective, wisely not calling attention to itself.

As for Andy, her arc is not dissimilar to Lindsay Lohan's Cady in 2004's "Mean Girls." Replacing high school politics for the office and fashion variety, Andy and Cady are a lot alike—nice, ambitious, free-thinking heroines whose change in lifestyle and desire to fit in leads them down a less-than-savory path toward becoming people they neither like nor recognize. Anne Hathaway (2005's "Brokeback Mountain") is perfectly cast as Andy Sachs, signaling a smooth, promising and altogether believable transition toward adult roles that service her talents much better than kiddie trifles like "The Princess Diaries 2: Royal Engagement" ever could. It is Andy that we follow at all turns—she is in every scene—and Hathaway runs with it, the generosity and wide-eyed accessibility she brings to her performance allowing the viewer to understand her actions and sympathize with her journey toward rediscovering who she is and what matters most.

In lesser hands, the part of Andy's boyfriend Nate would have been a thankless throwaway, but he, too, is written with fairness and respect. When Andy's job consumes all else, Nate is patient for as long as he can be before neglect and resentment take over. Adrian Grenier (2003's "Anything Else") brings more to Nate than expected, playing a loyal, affable man who can't help but be alarmed when he senses the old Andy slipping away from him. As well-regarded freelance writer for the New Yorker Christian Thompson, who helps Andy out in a time of need and possibly hopes for something in return, Simon Baker (2006's "Something New") fulfills his role with more than the typical layers inherent in a wolf in sheep's clothing. Baker is fine, but also upstaged in most of his scenes by odd-looking and thoroughly unattractive eyebrows that are too raised, too pronounced and too blond; for an actor who is usually quite handsome, he creepily looks like the Cheshire Cat in "Alice in Wonderland." Also putting in strong work are Emily Blunt, full of comedic wit and ravenous ambition as Miranda's second-in-command Emily, and Stanley Tucci (2004's "Shall We Dance"), whose straight-shooting editor Nigel Andy forms an unlikely bond with.

Technically, "The Devil Wears Prada" is A-list all the way, floating effortlessly from scene to scene via tight, assured editing by Mark Livolsi (2005's "Elizabethtown") that makes every one of Andy's hectic races against time to please Miranda pop with electricity and tension. The soundtrack is resplendent—Madonna, U2, Alanis Morissette and Moby are just a few of the artists whose work is used—each track evidently chosen with care and placed in an appropriate context that enriches the emotions of the characters and the tonal essence of the sequences they accompany. Additionally of note, the lush cinematography by Florian Ballhaus (2005's "Flightplan") paints the landscapes of Manhattan and Paris with a vivacious, glamorous, moody attractiveness rarely seen on film. The movie could scarcely be more aesthetically beautiful.

Perceptive, wise and hitting all the right notes, "The Devil Wears Prada" ranks right up there with 1988's "Working Girl," 1997's "Clockwatchers" and 1999's "Office Space" as one of the very best motion pictures about office life in memory. Director David Frankel lords over the proceedings with a firm handle on not only how to get big laughs through human behavior and acidic dialogue, but how to get them without trying too hard or sidestepping into cloying territory. Due to this fact, the film never gets too jokey, nor does the humor overpower the underlying poignancy of Andy's personal trek toward self-growth and coming-of-age in a dog-eat-dog world. That she is able to hold on to the goodness in her heart throughout her experiences at Runway is what resonates most in the viewer, empowering her and blessing the film with a necessary tinge of hope that carries through in the tough decisions she makes during the lovely final scenes. For all of its savagery and cynicism, the greatest attribute of "The Devil Wears Prada" is its surprising humanity.