Trey Parker and Matt Stone’s Comedy Central cartoon has been America’s best source of rapid-fire satire for a decade now, blasting hypocrites left and right and giving the final (and usually, the dirtiest) word on Elian Gonzalez, Terry Schiavo and numerous celebrity flip-outs. But the show’s authentic, filthy heart is the four foul-mouthed, truth-telling Colorado boys at its center. Eric Cartman, especially, is a creation for the ages — America’s wants and appetites rolled up into one pudgy package. The show’s best episodes are not the current-events riffs but the stories about the boys, like “Scott Tenorman Must Die,” in which Cartman concocts a Grand Guignol revenge against a tormentor involving cannibalism and a trained pony. Parker and Stone put the “id” in kid, and for that, we respect their authoritah.