These Louis Theroux documentaries from the BBC are fascinating.
The Most Hated Family in America
Louis and the Nazis
It's like a video version of Jon Ronson's Them. Theroux visits fringe groups in the US (in these cases, the Phelps family and a community of skinheads) and lives with them for a short time. The contrast between the domesticity of these families and the extremism of their beliefs is something he highlights, and it is a little bit unnerving--obviously, nazis have to make sandwiches for their kids too, but it's not usually what comes to mind.