Dave Kopel's interesting take on Michael Moore's Bowling For Columbine. At first, I thought he was naively giving Moore the benefit of the doubt, until I got to the end:

Some readers may doubt that Moore intentionally created an entire film whose subtext so thoroughly contradicts its literal text and that so effectively mocks its audience and its creator. My response is that we are long past the era of being chained to an artist's precise intentions.

Mockumentary it may be, but unlike This Is Spinal Tap, it was not created as a joke. The problem with Bowling is that it is not, by itself, an obvious and blatant lie. It's not until you are familiar with the actual facts that its ridiculous nature is apparent. I guess the same could be said of Spinal Tap, but then it never won any documentary awards that I know of.