Comedian Phyllis Diller is one of many comics who take a stab at the dirtiest joke in stand up in the documentary film The Aristocrats.

A successful exit from Park City, Utah, and the 2005 Sundance Film Festival, at least for consumer publicists -- those people in charge of handing out iPods, Xboxes, Phillips electronics, Levi's jeans and Timberland boots and numerous other free goodies to the celebrities in attendance -- means their "gift houses" are cleaned out. For these promoters, a happy festival is a towering stack of photos of stars holding up a shiny Motorola V3 Razr phone next to their smiling faces.

Experiencing a good Sundance is more difficult for the filmmakers in attendance despite how many bags of free clothes they ship home. The key Park City accessory for filmmakers -- even more important than a Blackberry -- is their film, and by the Jan. 29 Awards Night festivities held at Park City's cavernous racquet club, the post-Sundance status of their film is everything. Some films sold for millions. Others still wait for buyers. Below is the 2005 Sundance Class of Films That Matter -- and will most likely impact audiences far away from the Park City ski slopes.

King of the Hill: Hustle & Flow
For Hustle & Flow writer/director Craig Brewer, Sundance was a bookend of good news. Early into the festival, Paramount Picture announced a $16 million deal for the film, a $9 million acquisition for Hustle & Flow and a commitment to finance two more of producer John Singleton's films at $3.5 million each. At the festival's finale, on Awards Night, Hustle & Flow received prizes for cinematography and the coveted American Dramatic Audience Award, further proof of its mainstream popularity.

A Memphis-set drama about a pimp (Terrence Howard) trying to become a successful rapper, Hustle & Flow failed to win over the majority of critics who took issue with the film's clumsy melodrama. Still, the opinions of festival critics don't matter as much to a young filmmaker when he has a potentially huge commercial hit on his hands.

The Laughmaker: The Aristocrats
For their documentary The Aristocrats, the raunchiest, laugh-out-loud funny history lesson you'll ever experience, stand-up comics-turned-co-directors Paul Provenza and Penn Jillette (the portly member of the comedy team Penn & Teller), film an army of comics who offer their takes on the dirtiest joke in stand-up, the description of the filthiest act imaginable to a talent agent. The Aristocrats -- purchased at the festival by THINK Films, which plans a late 2005 release -- is as raw as the joke it reconstructs, a matter-of-fact series of face-the-camera interviews by a Who's Who of comics and comic writers. Worlds apart from the typical, serious Sundance political documentary, The Aristocrats reminds us that a documentary can succeed with nothing more than a fantastic, filthy joke.

Slick, Slick, Slick: Thumbsucker
Young actor Lou Pucci won a Special Jury prize for his dead-on performance as awkward teen Justin Cobb in Thumbsucker. But the core accolades belong to Mike Mills, the graphic artist and music-video director who makes his feature filmmaking debut with this visually dazzling, surprisingly funny and emotionally rich adaptation of Walter Kirn's novel. Coming-of-age stories are nothing new at Sundance or the suburban multiplex, but Mills makes Justin's struggles with medication addiction rich, surprising and unforgettable.

Hipster Artist Makes Good: Me and You and Everyone We Know
Multimedia performance artist, author and short film director Miranda July arrived at Sundance with an avant-garde résumé a mile long and leaves with a hit debut feature film, the lovable, quirky romance, Me and You and Everyone We Know (IFC Films plans a summer 2005 release). July stars on both sides, playing a lonely artist and elder-cab driver who struggles to start a romance with a single department store salesman (John Hawkes).

July has exhibited her short films at the Museum of Modern Art and the Guggenheim and has written stories in The Paris Review and The Harvard Review. Me and You and Everyone We Know brings July to the commercial world outside the avant-garde community -- and everyone is in for a treat.

Feel Good Music: Rock School
Young boys and girls, guitars and Marshall amps equal a ton of fun in Rock School, director Don Argott's rousing music documentary. The film's over-the-top subject is Paul Green, the motor mouth head of the Philadelphia-based Paul Green School of Rock Music, which teaches approximately 120 students between the ages of 9 and 17 how to perform Rock music. The film flits between Green's high energy banter and the kids' performances, climaxing at a Frank Zappa festival in Germany.