But to get to the top 25 quicker, let's list the rest of the runners-up.
Sweeney Todd: The Demon Barbar of Fleet Street
Ghost World
Borat: Cultural Learnings of America for Make Benefit Glorious Nation of Kazakhstan
Adaptation
Dancer in the Dark
Billy Eliot
Kiss Kiss Bang Bang
Juno
Unbreakable
The Mist
Narc
Insomnia
Little Children
Spider
Titus
Wall-E
Chicago
Million Dollar Baby
A History of Violence
Iron Man
The Life Aquatic with Steve Zissou
Paranoid Park
While Gus Van Sant's Elephant won the Palme d'Or at Cannes, I think this film is better. This story of a teenage skateboarder who commits manslaughter is absolutely mesmerizing to watch. With films like this and the riveting Milk, Van Sant has transcended from mere film director into a true artist.
Superbad
Batman Begins
Children of Men
Mulholland Drive
The Tao of Steve
A movie that theorizes that all guys named Steve are awesome. I can't understand why I would want to include it here.
Serenity
The Hangover
Hostel
Evoution
Oh, so greatly under appreciated. Though it lacks the unique magic of Ivan Reitman's earlier movie Ghostbusters, which it closely resembles, Evolution is none the less a really fun movie to watch.
Spirited Away
Super Troopers
High Fidelity
Donnie Darkko
No Country for Old Men
Stranger Than Fiction
Monsters, Inc.
Milk
A.I. Artificial Intelligence
Bowling for Columbine
Requiem for a Dream
In the Loop
American Gangster
V for Vendetta
The Descent
Gladiator
Momento
Lost in Translation
Pan's Labyrinth
Ratatouille
Anchorman: The Legend of Ron Burgundy
Observe and Report
The Bourne Trilogy (The Bourne Identity; The Bourne Supremacy; The Bourne Ultimatum)
The 40-Year-Old Virgin
Fahrenheit 9/11
Taken
The Incredibles
Traffic
X-Men/X-Men 2
But avoid Brett Ratner's dog turd of a sequel, X-Men: The Last Stand.
Star Trek
Training Day
Collateral
Best in Show
Shrek
Cache
What Planet Are You From?
Cast Away
The Contender
Infamous
As good as Bennett Miller's Capote was, Douglas McGrath's take on Truman Capote's efforts to write In Cold Blood was actually better. Philip Seymour Hoffman took home an Oscar, but Toby Jones was born to play the role. If this film had made it to theaters first, Hoffman would probably still be waiting for an Oscar.
The Perfect Storm
Kill Bill, Vol. 1 & 2