'Jesus Camp' doesn't have any narration, it only shows a glimpse of the religious kids camps. It's completely left up to the viewer to think the the camps are crazy or awesome. It's brilliantly done.
I don't remember if there was narration or not, but 'Word Wars', about competitive Scrabble, doesn't take a side (there's no side to take, really). It simply shows the competitors and the kind of zany world they live in.
I don't want to question your examples, but lack of spoken narration doesn't automatically lead to an unbiased documentary. It's pretty easy to build a narrative just through visuals, by selectively showing certain aspects and ignoring others.
I don't remember if there was narration or not, but 'Word Wars', about competitive Scrabble, doesn't take a side (there's no side to take, really). It simply shows the competitors and the kind of zany world they live in.