Sicko is Michael Moore's most mature work to date and almost certainly his best film. As Hillary Clinton found out the hard way, health care isn't a particularly sexy topic, but with his usual populist's touch, Moore has crafted a film that's intellectually and emotionally gripping from start to finish. Without oversimplifying the complex issues involved, Moore deftly reduces the problem to its most basic elements: don't we all have a responsibility to look after the weak and the sick? No less strident a polemic than Fahrenheit 911 or Bowling for Columbine, at heart, Sicko is a passionate plea for solidarity and compassion.

Moore uses his trademark quips and stunts more judiciously than ever, keeping his own divisive persona off-screen as long as possible and letting his subjects speak for themselves. The film opens with devastating personal stories about uninsured Americans stitching up their own gaping wounds and having to choose which finger they can afford to save. However, Sicko isn't about them: instead, there are more horrific tales of woe, this time by people who do have insurance, cancer patients and sick babies who are denied life-saving treatment. An inside look at the workings of HMOs explains why. Over thirty years ago, President Nixon established a for-profit approach to medicine; for American insurers, every claim denied is money in the bank. Powerful financial interests would like to keep it that way.

With a catchy soundtrack and commentary that straddles the line between black humor and righteous disbelief, Sicko then takes us to Canada, England, and France to see how the sick are treated elsewhere. To his somewhat disingenuous shock, Moore discovers free, universal health care everywhere he goes. He interviews patients, doctors, and expatriates who puncture the myths Americans are fed about "socialized medicine." Doctors seem to live very well, patients aren't made to wait a long time, and everybody laughs at him when he asks how much they have to pay for treatment.

After he hears that inmates at the Guantanamo Bay prison camp receive free, state-of-the art medical treatment from the American government, Moore is ready for his final stunt. He takes a group of seriously ill 9/11 responders -- heroes once lionized and now forgotten -- to the prison camp, facetiously asking that they be treated as well as suspected terrorists. It's no surprise that the guards at Camp X-Ray turn them away, but the sick rescue workers finally do receive the care the American system denied them: in a public Havana hospital. In a poignant moment that neatly summarizes Moore's argument, an impoverished Ground Zero volunteer is reduced to tears when she finds out that the same inhalers that cost her $120 in the U.S. are available in Cuba for a nickel.