Starring Greg Kinnear, Toni Collette, and Steve Carell. Rated 14A. Opens Friday, August 4, at the Cinemark Tinseltown and the Fifth Avenue Cinemas

Tolstoy wrote about unhappy families, as he famously explained, because they're all different. And he never even saw one packed into a crappy VW camper van.

Being neither Tolstoy nor dead, we are able to spend time with the well-named Hoovers. They suck but are perhaps the most entertainingly depressed clan ever to dysfunction together from Albuquerque to Los Angeles on a seemingly pointless but still life-altering excursion.

Lame dad Richard (Greg Kinnear) is a terminally cheerful failure; the multistep program he developed to motivate himself is so transparently post–Tony Robbins that he can't even get his family to listen anymore. He's constantly undercut by wife Sheryl (Toni Collette), who doesn't seem to enjoy anything much any longer except making hubby squirm.

Sheryl's idea of “getting dinner”  is to haul buckets of no-name fried chicken out of the car for a special meal when older brother Frank (Steve Carell) comes to stay after a failed suicide attempt. The nation's number-one Marcel Proust scholar, Frank is doubly distraught since a beloved male grad student left him for the number-two Proust man. Because he must be watched, she bunks Frank down with her teenaged son, Dwayne (The King's Paul Dano, the new face of disaffected American youth). Often hiding beneath a giant poster of Friedrich Nietzsche, Dwayne has taken a vow of silence while awaiting his chance to train as a fighter pilot.

The only semi-normal Hoover is Olive (Abigail Breslin), a chubby seven-year-old exuding the unforced optimism for which Richard would gladly give his left nut. She draws strength from the attentions of Grandpa (Alan Arkin), an otherwise foul-mouthed heroin addict with zero patience for his son's schemes. “I took Nazi bullets for this crap?”  he asks, semi-rhetorically.

What saves the Hoovers from life in a sitcom written by Samuel Beckett is Olive's determination to enter a preteen talent contest called Little Miss Sunshine. So they all pile into said van to leave their shabby New Mexico bungalow for the mythical splendours of Southern California. The event turns out to be a hideous parade of JonBenet Ramseys, with all the easy-target creepiness that implies, but this is incidental to the journey””which is good, because whatever hitches exist in Michael Arndt's otherwise tight screenplay are found in the destination part of the story.

The rest offers textbook uses of economy and imagination from codirectors Jonathan Dayton and Valerie Faris””not to mention hilariously underplayed acting from the whole ensemble. If you were wondering if Carell is into more than remembrance of shticks past, Sunshine is the best place to look.