Recently I rediscovered the early 90s series, The Adventures of Brisco County, Jr. This was a TV western that incorporated a lot of fantastic and science-fiction elements, but mostly humour. Starring the incomparable Bruce Campbell, the show lasted one season, though it managed to finish the main story arc of that season: Brisco's hunt for the outlaw John Bly, killer of his lawman father. Although the show was fantastic, it was not renewed for a second season. The main reason for this was low ratings, but I have my own theories:

1. The show was aired on Fox. Fox is the network that kills promising TV series. Along with Brisco County Jr., Fox also killed Brimstone, Firefly, Fastlane, Space: Above and Beyond, Futurama, and Arrested Development. (I'm sure I'm forgetting some.) Fox sets these shows up for failure by placing them in lethal spots in the broadcast schedule (the infamous "Friday night death spot" that killed Star Trek back in the 1960s, for example), or shuffles them around the schedule making it difficult to build an audience, or not allowing these shows the time to develop a proper audience. Fox instead promotes dreck like COPS, Beverly Hills 90210, Melrose Place, When Animals Attack, and Married with Children (to be honest, I found the latter entertaining most of the time, but it couldn't hold a candle to some of the cancelled series). The Simpsons and The X-Files appear to be the only atypical (at the time) and promising series that didn't get cancelled by Fox and went on to incredibly successful runs, only to peter out on a whimper in the case of the X-Files, or continue ad naseum while its fresher, hipper successors make it look like the tired and old franchise it is in the case of the Simpsons.
   
   To be fair to Fox, I should note that in most cases, Fox was the only network willing to take a chance on shows like the above, while the "Big 3" played it safe, preferring instead to rip off Fox's successful ideas. The success of the X-Files, for example, led to several knock-offs, most of which sucked (Dark Skies, anyone?). These days, though, it looks like the networks are out of good ideas. Creativity is coming from cable and syndication these days.
   
2. Brisco County was a Western in a time when the genre was starting to die off. Although the genre got a bit of a shot in the arm from the Lonesome Dove miniseries and Dr. Quinn, Medicine Woman, by the mid-90s is was clear that the genre was just about done. The influences of the Western were quiet profound on American fiction, TV and cinema. Many aspects of the Western genre could be found in action films, science fiction, and martial arts movies. But the Western itself seemed to be on its last legs (this is before the more recent revival thanks to shows like Deadwood).