The last minutes of Pan's Labyrinth. It's all so... beautiful...
"I taught young boys to drop fire on each other..." The sacrifice scene from Apocalypse Now. The cinematography, the poem, the whole scene is extremely well done.
Wall-E and Eve's dance in space. If Wall-E doesn't win an academy award for best animated film, I'm going to write an angry letter. This is the most beautifully animated scene I've ever watched, and it's marvelously romantic.
"Mien fuhrer, I can WALK!" Dr. Strangelove, ushering in the nuclear apocalypse. I've analyized every inch of this film to death, and this scene is so beautifully dark, ironic, and... well, triumphant I have to include it here.
The Hunchback of Notredame (the Disney, animated version), the "Hellfire" sequence. I will never be the same after watching that.