Of the nominated films, "No Country For Old Men" was the film that should have won. "There Will Be Blood" was spellbinding, but, I think, like Paul Thomas Anderson's "Magnolia," ultimately didn't come together into a satisfying narrative.
I've written here before that the thematic arc that has been imposed upon "Blood" by critics, of capitalism and religion locking horns, doesn't quite fit. But it's a measure of the movie's flaws that it's so misunderstood. Most critics have also agreed that it's a film about a pathological misanthrope, but Plainview loves his son, even though he is flawed as a father. And he wants so badly to embrace the man claiming to be his brother that he engages in self-deception to allow himself to do so. I think it's a film about loneliness.
But I walked out of the theater not knowing what it was about at all, and that's the messiness of it. It's dense but unstructured, and the narrative seems to slacken to accomodate the performances.
"No Country" is unsatisfying too. It builds up and then abruptly dissipates, but it's in service of the narrative and of the theme, which is the futility of the efforts of man in the face of fate or chance or God.
Of course, I think "Ratatouille," was the best film this year, and it's a little odd because it is the thematic opposite of "No Country," since the moral of "Ratatouille" was that excellence is vindicated, and the moral of "No Country" is that ability is brought to ruin by chance.