Although I personally appreciate Breaking the Waves more than Dancer in the Dark (its religious voracity, the isolation of the location, and painting interludes strike me more) gonna say out of these noms I'll totes campaign for Dancer in the Dark -- this iz one of the first LVT'z my dad showed me over a decade ago, that it means something to him means something to me.
I've only seen it twice -- and remember more from DitD beat-for-beat than I do from some flicks I've seen more than one hand can count. It's imprinted onto me as if part of her working machine.
Some films achieve their power not only from whats on screen but the atmosphere that it imbues around it.
Mulholland Drive
Southland Tales
Twin Peaks: Fire With Me
Richard Kelly cites going to see FWWM with a dozed off date as the moment that sparked his entire cinematic mind. Obviously then emulates this date within a Donnie Darko scene.
Three totalizing pictures of a larger, violent, societal whole. Swirling in the surreal and tinged w/ unique humor. Over, say Chinatown, I'm gonna vote for movies that coulda only come at one time from a crew's unifying aesthetic off the beaten path. Like Chinatown definitely iz that good, but I've gotta trim somehow! And cuz obvi I'm hurt y'all dont think Tromeo & Juliet belonged on here ;) Of course my personal tuff list of twenty includes The Terrorizers and The Thing.