1997–2010; also “Hank of the Hill theme song“ and “King Hank theme song”
R.I.P. Brittany Murphy.
The theme song from King of the Hill is officially entitled “Yahoos and Triangles.” It is by the Arizona-based band The Refreshments—known in the nineties for their hit single “Banditos.” It is said that the band often played the theme song at soundchecks for their shows.
Now, while even the band calls their own song “Yahoos and Triangles,” the song is credited as “King Of The Hill Theme” in the official soundtrack of the series. The full version of the song lasts a little more than two minutes.
Below is the full/extended version of the song.
And because FOX is unreasonably (stupidly) strict with copyright issues, below is the only decent official opening sequence we can find—uploader had to make silly modifications.
Which is also why there are hoards of intro parodies for the KOTH intro like the one below.