Who doesn't love a wedding? For that matter, who doesn't hate them, too? Among the rituals that comprise life's rich pageant, few can match a wedding for sheer joy and bare-knuckled dysfunction. Like any good exchange of nuptials, "Rachel Getting Married" engulfs a wealth of conflicts, resentments and unresolved rivalries, and yet you might wind up shedding tears of happiness.

Director Jonathan Demme ("The Silence of the Lambs") goes for the shambling, improvisational feel of a Robert Altman picture, but there is little doubt that the script, by first-time screenwriter Jenny Lumet (daughter of filmmaking great Sidney Lumet), is exacting. At first blush, "Rachel Getting Married" bears the tenets of rote domestic melodrama, but its level of humanity is rare. If the picture occasionally strays, its understanding of family "” not to mention the twisted dynamics that govern it "” is uncanny. You sense that these characters actually existed before the opening credits.

The title refers to Rachel, but the film's central character is Kym (Anne Hathaway), an acerbic young woman who is furloughed from drug rehab to attend her sister's wedding. Quick-witted and unfailingly self-absorbed, Kym is a tsunami disguised as a chain-smoking smart-ass. She shrinks under the well-meaning smothering of her father (Bill Irwin, "Across the Universe") and engages in verbal sparring with older sister Rachel (Roesmarie DeWitt, TV's "Mad Men"), who is about to marry a musician (Tunde Adebimpe, of alt-rock band TV on the Radio). Kym is shameless and embarrassing, and you can't take your eyes off her.

FAMILIAL WARMTH
Never far from the fragile veneer of familial warmth is a tragic incident from the woman's past. It haunts her, as it does her family, and yet "Rachel Getting Married" is, miraculously, not an exercise in despair.

The film's style is loose-limbed. Demme and cinematographer Declan Quinn reportedly resisted mapping out shots or camera movement beforehand. The naturalistic approach draws viewers into the complicated maze of relationships. There is no shortage of pathos here, but "Rachel" is smart enough to realize that pain often shares the same space with compassion and love.

Hathaway proves that she has acting chops to match her beauty. Seriously, this is the same girl from "The Princess Diaries"? It's a powerhouse performance, and one certainly in line for an Oscar nomination, but she is just part of a terrific ensemble cast. Dewitt has a commanding presence, and more than holds her own in scenes with Hathaway. Also effective is Debra Winger, marking a rare return to the big screen as Kym's emotionally guarded mother.

There is much to embrace in this sprawling, occasionally messy and mainly enthralling picture. Demme's love of music has long been evident, having helmed first-rate documentaries on Neil Young and the Talking Heads, and he infuses "Rachel" with the constant flow of diverse songs.

Moreover, the movie celebrates multiculturalism in the most novel way possible: by not making a big deal of it. It's a small touch, but an enlightened one, and it is among many reasons that "Rachel Getting Married" is among the year's best films.

"”Phil Bacharach