In a world of raunchy comedies and edgy plotlines, King of the Hill broke the mold during the late '90s and into the 2000s with its special brand of tame, relatively clean comedy. Focusing simply on the goings-on of a humble Texas family and their neighbors, King of the Hill thrived on the inherent hilarity of its quirky characters and their small-town problems. That comedy wouldn't thrive on its own, though.
King of the Hill stayed alive during its run through various storylines and changes that always kept the series fresh while leaving the audience wanting more. These include the romance between Bobby and Connie, Peggy's constant struggle to find a job, and the reconstruction of the Gribble family. Despite some of the series' best beats, not every story had decent follow through with some just being dropped and forgotten entirely.
10 Hank's Japanese Brother
It's no secret that Hank Hill's rough childhood was very much because of his angry and worldly father, Cotton Hill. That same worldly behavior is also responsible for some interesting additions to the family, and not just good ol' Hank. In the "Returning Japanese" arc, the series revealed that Cotton actually had another son that he didn't know about with a Japanese woman in the aftermath of World War II.
That would be Junichiro, a robotics engineer every bit as strict and endearing as Hank, who helps the Hills when Cotton goes on a rampage throughout Japan. As interesting as this mysterious family member was, Junichiro is sadly never referenced again in the series.
9 Jack The Crazed Barber
In "Hank's Bad Hair Day," Hank attempts to show Bobby his longtime barber, Jack, but is surprised to find both the old man's skills and mind dwindling away. After receiving a couple of bad haircuts from him and seemingly breaking up with him for good, Jack admits in this episode that he's finally quitting the barbershop permanently. It was later revealed that Jack was actually arrested after a high speed chase.
As comical as it was, the series doesn't bring this up again when Jack surprisingly returns in "My Hair Lady" to give Luanne a new job. The story from there kind of skirts around the fact that Jack is not only mentally unwell but should have a history of dangerous behavior at this point.
8 Lucky's Job (Or Lack Thereof)
The story of Lucky Kleinschmidt is one of redemption intertwined with various other pitfalls. One of those pitfalls at a Costco would fortunately grant him a $53,000 settlement. However, after he marries Luanne and has a child with her, he finds his funds suddenly dwindling. To fix this, he initially gets a job with Dale's Dead Bug.
However, a mishap on the job had Lucky actually suing Dale Gribble and, after some other shenanigans, his own lawyer, granting him another $53,000 settlement. While that settlement should be pretty hearty, it doesn't seem like enough to support an entire family for years, yet the series never touches on Lucky's work life again.
7 Tammi Becomes A Part Of The Family
In the episode "Ho Yeah!," the Hills are surprised to find that they've taken an escort into their home. Tammi Duvall met Buck Strickland in Oklahoma and he then hires for Strickland Propane. Hank and Peggy take a liking to her and decide to welcome her in their house. Unfortunately for them, Tammi not only falls back into her previous source of income but starts to get harassed by her former "employer."
While he initially tried to kick Tammi out, Hank sees how genuine Tammi has become and inevitably saves her from her old boss. It's implied at the end that Hank still welcomed Tammi into his home, yet she's never seen again in the series, aside from an quick background appearance in "Lucky's Wedding Suit."
6 Bill Dating Kahn's Mom
Bill Dauterive's troubled romantic life has been a major pillar in the series, with his most likely chance of finding love coming in the episode, "Maid in Arlen." Here, he hires Kahn's mom, Laoma, as a maid but subsequently starts dating her. Surviving some romantic sabotage attempts by Kahn, the two decide to stay together. However, this is the only time that his romance is seen.
In the following episode, "The Witches of East Arlen," Bobby predicts with some tarot cards that Bill's newfound relationship was destined to fail, but the story doesn't actually show what happens, leaving a little too much to the audience's imaginations.
5 Buck And Miss Liz
Buck Strickland really has been more antagonist/obstacle across the series than an actual character, as evident by the fact that he hardly changes as the series went on. He started the show as a drug-addled miscreant and finishes the series the same way. His greatest attempt at redemption came in the two-parter for Debbie Grund's murder.
His wife, Miss Liz, gets fed up with his behavior and, via a nasty divorce proceeding, she takes control of most of Buck's assets. However, once the dust settled on Debbie's murder case, the two seem to have gotten back together. Despite this, Buck doesn't change after this episode. Not only does he continue his toxic behavior, but Miss Liz is never to be seen again.
4 Luanne's Roommates
Luanne has had quite the evolution across the series. She initially debuted as Peggy Hill's traumatized niece from a very unstable, trailer park upbringing. However, as the series went on, she took on greater and greater responsibilities, moving further away from the Hills. One of the biggest pushes she takes is when she decides to rent a house with a few college roommates.
As gilded as the opportunity seemed, Luanne has a hard time getting along with them and even harder time getting them to pay for things. She eventually finds her way in this arc, but her roommates are never seen or mentioned again, and the series never touched on how she was able to afford her house by herself during her college years.
3 Boomhauer And Katherine
Jeff Boomhauer was a sadly underutilized character across King of the Hill. While he wasn't as wacky as Dale or Bill, Boomhauer had a calm demeanor and worldly lifestyle that could've propped up plenty of storylines. One of the biggest missed opportunities to really make Boomhauer his own character was with his complicated romance with Katherine Hester.
Katherine was his old high school girlfriend who broke up with him when she left for college. In "Patch Boomhauer," she would return to Arlen only to marry Boomhauer's brother, Patch. Things fell apart, however, and Katherine began to realize her feelings for her old flame. Despite this, nothing ever comes out of the two's nostalgic love.
2 John Redcorn Trying To Connect With Joseph
The story of Dale and Nancy's complicated romance not only provided plenty of gags during the early series and interesting plot threads for the Gribbles in the later series, but it also elevated John Redcorn's character. Prior to his breakup with Nancy, John Redcorn was simply just used for jokes related to Nancy's infidelity.
Once the two separated, he began some sincere arcs where he both tried to figure out his identity as well as find ways to connect with his biological son, Joseph. The latter would lead to interesting developments in episodes like "Spin the Choice" and "Vision Quest," but this storyline would get dropped once John Redcorn started focusing on his music career.
1 Peggy Trying To Get Pregnant
The story of Hank and Peggy's non-existent second child helped elevate nearly the entirety of Season 3. Once Hank and Peggy start feelings the affects of their age, the two decide to have another go at having a child. This would create classic episodes such as "Pregnant Paws," "Next of Shin," and the two-parter involving Peggy falling out of a plane.
After the premier of Season 4, however, the series never brings up the storyline again. Hank and Peggy no longer seem to be trying to have a second child, and Peggy oddly never brings up what was a heavy insecurity during Season 3.