It's an unmistakable sound, the silly, sweet thwap-thwap-thwap of a naked man happily wagging his genitals. And it isn't something you often hear in a movie (or at a movie, hopefully), but "Forgetting Sarah Marshall" confirms that Judd Apatow and his de facto filmmaking collective have essentially reinvented the romantic comedy. In their hands, the timeworn clichés seem less cloying and more, well, ballsy, fortified by the infusion of testosterone (or: raunch and humiliation) that no one noticed was missing.

Our unclothed friend is Peter (Apatow regular Jason Segel, who wrote the relentlessly funny script), and the reason he needs to forget Sarah Marshall becomes clear in the uncomfortable opening scene, when Sarah jilts Peter in all his bare-assed glory. Weepy Peter sloshes around in self-pity for as long as allowed by his tough-love stepbrother (SNL's sneaky Bill Hader, "Superbad") and then jets to exquisite Hawaii for some mending. Unfortunately, Peter chooses the exact hotel where Sarah, a TV star (she's on "Crime Scene: Scene of the Crime" with a hammy Billy Baldwin), is vacationing with her new rock-god boyfriend, Aldous Snow (UK import Russell Brand, who would steal this movie without mercy from a lesser cast).

Naturally there's a beautiful girl to take Peter's mind off of Sarah and her charismatic lover, and though hotel clerk Rachel (classy, revelatory Mila Kunis from "That ‘70s Show") has thuggy baggage of her own, she can't help but be charmed by the down-to-earth Peter, a composer whose dream project is a musical starring a Dracula puppet. Sarah, of course, begins to see Peter in a different light, but Segel's honest writing wouldn't dare let Peter off the hook, telling both sides with a revealing flashback about the slow demise of their relationship from Sarah's point of view.

His script clearly autobiographical in some way, Segel is fearless whether he's blubbering or showing the goods, channeling an everyday vulnerability that movies rarely get right. Brand takes a character that's usually one-dimensional and gives Aldous a likability, almost a wisdom, that even Peter can't resist. The ladies are slightly underserved here, but watch for Jonah Hill ("Superbad") as a waiter with a big man-crush on Aldous ("I just went from 6 to midnight"), as well as lovely Paul Rudd, a surfing instructor prone to totally baked truths like "When life gives you lemons, just say ‘Fuck the lemons' and bail."

"Forgetting Sarah Marshall" is as predictable as any rom-com, but there's predictable-boring and predictable-satisfying. This is the latter, tweaking the rules as it adheres to them. It's the chick flick done - refreshingly, respectfully, and profanely - from the thinking man's point of view. I'd rename the genre if I weren't 92 percent certain that "dick flick" already means something else.

Javier Bardem famously won the Supporting Actor Oscar this year for "No Country For Old Men," but if I were Empress of Hollywood I'd snatch it back and bestow it upon Casey Affleck for his phenomenal turn in the criminally forsaken "The Assassination of Jesse James by the Coward Robert Ford." Playing the titular murderer opposite a fine Brad Pitt as the legendary criminal, Affleck undergoes a heartbreaking transformation from innocently creepy sycophant to bitter, regretful man. "Do you want to be like me, or do you want to be me?" Jesse snarls, and we watch Bob's naive dreams of lawless grandeur shatter as his only hero barely hides his contempt.

Australian filmmaker Andrew Dominik (2000's "Chopper") takes an astonishing leap forward with his second feature, which sat on studio shelves for a time, maybe because the suits didn't know how to market such a breathtaking achievement. A dark, atmospheric Western with sprawling imagery by seven-time Oscar winner Roger Deakins and a score by Nick Cave (he honed his outlaw twang on 2005's "The Proposition"), the title prophecies how it will end. The pleasure - and there is much of it, with a crackerjack supporting cast that includes Sam Rockwell and Paul Schneider - lies in the journey, as they say, not the destination. Please don't miss it. 

Forgetting Sarah Marshall

(R), directed by Nicholas Stoller

Now playing

The Assassination of Jesse James by the Coward Robert Ford

(R), directed by Andrew Dominik

Screens Wednesday, April 30, and Thursday, May 1, at the Dryden