Movies in which a single mood takes a front seat to plot or character. A lot of mine can be summed up with the words "longing" or "disillusionment," but that's because of the way I'm wired. This isn't an exhaustive list, but if there is a movie you think fits the theme, please feel free to bring it up in the comments.
See also: everything Terrence Malick has made.
List inspired by Ken Priebe.