Michael Moore's first major film was one of his best in my opinion for two reasons. First off, since he did not yet have a trademark style, he did not try to go over the top in this film as much as he does in his subsequent efforts. He does his normal routine of tracking people down in an effort to embarrass them by asking them pointed questions, but for most of the film he lets the story and the citizens of Flint do the talking. As you probably already know, this is the story of Moore's hometown, Flint, Michigan, and the utter despair that fell upon it after GM began shuttering auto plants under the supervision of then CEO Roger Smith. The film really highlights how clueless Flint's elite are as to the suffering that all of this "consolidation" is causing. At one point in the film Moore is talking to some wealthy people at a party who seem to think they are doing the unemployed some kind of favor by hiring them to act as living statues at one of their fêtes. When he asks the party goers about what is going on in Flint they seem somewhat offended that there is such "negative publicity" circulating and say there should be more emphasis on the positive things going on in Flint - they name the symphony and the opera. Ah yes, let them eat opera glasses!
The second reason I consider this film to be one of Moore's best is that even though this film was made in 1989, it is still interesting and relevant today. This is because the contrast between what average working people have to endure - the struggle to find secure jobs with decent benefits and their increasing vulnerability - and the desire of the captains of industry to improve the bottom line at any cost ... as long as it doesn't cost them ... has only worsened and deepened over the last 21 years since this film was first made.