The instant reviews of “Sicko,” Michael Moore’s new movie, are beginning to trickle onto the Web. Eric Alterman, who has taken his “Altercation” blog from to Media Matters, calls it “by far Moore’s best film: good humored, compelling, and, amazingly, it’s actually fun.”

David Corn, Washington editor for The Nation, agrees that “Sicko” is “the best film in the Moore canon.” “It’s not as tendentious as his earlier works,” Corn writes on Capital Games, his blog for The Nation. “It posits no conspiracy theories. The film skillfully blends straight comedy, black humor, tragedy, and advocacy. You laugh, you cry — literally. And you get mad.” (In 2004, Corn wrote in a Capital Games post that Moore’s “Fahrenheit 9/11” was “overly conspiratorial” as well as “problematic and self-defeating.”)

On his personal blog, Corn adds of “Sicko”: “It does not reveal what most Americans don’t already know. But the film — quite moving in some parts, quite funny in others — presents a well-crafted indictment and diagnosis of a sick, sick system.”

Economist and libertarian Arnold Kling worries that Alterman and Corn are right about the film’s effectiveness, despite what he perceives as its flaws. “I found the movie to be very non-threatening intellectually, because it was so obviously one-sided,” Kling writes at his blog, EconLog. “Contrasting French yuppies with American homeless people does not really prove anything.” Still, Kling says:

On the other hand, it could have a tremendous political effect. The woman next to me broke down and wept during a scene in which a group of Cuban firefighters salutes three 9/11 rescue workers brought by Moore to Cuba for treatment. My guess is that this woman’s reaction to the film was more typical than mine.