Grizzly Man (2005)

Werner Herzog makes an unromantic and yet very personal film about someone he never met without any melodrama.

An actor turned extreme environmentalist named Timothy Treadwell spends his summers living among grizzly bears. He films his dangerously close encounters and then travels the United States promoting the conservation and protection of these animals. After 13 summers, he is attacked and eaten by a bear.

The director narrates between interview scenes and stunning footage that Treadwell produced. I was thoroughly moved not so much by treadwell's dedication/insanity, but by how sensitively and rationally Werner Herzog presented this troubled man.

IMDB