As I hinted earlier, I think that King of the Hill in its early seasons was a richer, darker show than it is now (it's still good, but it's become more of a comfort-food kind of show), with creator/showrunner Greg Daniels pulling off some very interesting and even daring stories and story arcs, with the kind of thematic depth and emotional richness that even The Simpsons didn't have in its best years. Here are two clips that illustrate what the show was doing at that time.
1. The conclusion of the greatest episode of KotH, the Christmas episode from the third season, "Pretty, Pretty Dresses" (written by Paul Lieberstein, who has followed Daniels to The Office). This has the darkest premise of any Christmas episode in the history of sitcoms, or maybe any sitcom episode at all: Bill (voice of Stephen Root) becomes so depressed about his divorce from his wife Lenore that he repeatedly tries to commit suicide. Finally, Hank (voice of Mike Judge), giving him some tough love, confronts Bill with the fact that Lenore is never coming back, but instead of curing him, it pushes Bill over the edge: the only way he can get Lenore back is to become her, so he puts on her old dress and becomes convinced that he is his ex-wife. Depression, suicide and insanity -- just what you would expect in an animated sitcom episode.
2. A more lighthearted episode, season 2's "Hank's Dirty Laundry," is about Hank suffering the ultimate indignity: the video store's computer erroneously says that he rented and never returned a pornographic movie called Cuffs and Collars, and his application for a credit card is turned down on that basis. But as the episode goes on, we start to realize that Hank is less and less concerned about being falsely accused of renting pornography, and more and more concerned about the simple fact that a computer error has falsified a detail of his life. In the climactic (no pun intended) scene, an anonymous tipster gives him a collection of pornographic movies, and Hank defends his honor by becoming an expert on porn and defending himself in court. Having a character as straitlaced as Hank talk about pornography without acting out of character is a very neat trick, and Daniels and writers Jonathan Aibel and Glenn Berger really pull it off. There's also a "B" story about Bobby Hill mistakenly thinking that his parents are going to throw him a surprise party.