The entire opening montage of Up is by far the most beautiful, moving, and heartbreaking series of images and music put together that I've ever seen on film.
Others worth mentioning:
The opening of Disney's Dinosaur.
The first act of WALL-E.
The end of Lost in Translation
Various scenes from various Jim Jarmusch movies... the man is a master of dialogue, but also a master of silence. Dead Man, Broken Flowers
Tarantino classics: Every one of his singularly directed films has at least one scene(or part of a scene) in them that is amazing and totally lacking dialogue. The opening credits in Reservoir dogs, Vic walking out to the car to get gas and coming back inside ignoring the screams, The dance off in Pulp Fiction, Bruce Willis returning to his apartment and killing Vincent, Bruce Willis escaping the gimp and then selecting a weapon, etc etc etc.. it goes on and on.
I'll probably get **** for this one, but the scene in the first Transformers where more Transformers start to land. There's a bit of dialogue(Are you the tooth fairy?), but it's by far the best scene in the movie and mostly silent.
Also, my two favorite Scott movies, Blade Runner final cut and Kingdom of Heaven DC, have fairly long stretches without dialogue and they are pretty much perfect films, so go from there.