Every writer has at least one good idea. One thing that folks who read their work find fascinating. The problem is, we tend to go back to the successful idea over and over again. This leads us into the problem of repetitiveness and its follower boredom.
If I say “The A Team,” your mind might race to BA Baracus saying “I pity the fool!” or John “Hannibal” Smith saying “I love it when a plan comes together.” Those are entertaining characters, but the show ended up being terribly formulaic. Somebody hires the A Team, they do some digging, they are almost defeated by the bad guys, they create something from whatever is around, and they narrowly escape the Military Police at the end of the day.
Most shows have a similar problem. Matlock, Murder She Wrote, MacGyver, The Greatest American Hero, Duck Dynasty (Yes, we have been watching that on DVD lately), Superfriends, Monk, etc.
As a writer, I find it more informative to see how these shows pull themselves out of their ruts rather than simply watching for how they repeat themselves over and over. Let me give you a few examples. Monk crafted an episode that was entirely black and white and was styled after a film noir detective show (“Mr. Monk and the Leper”). Murder She Wrote used an episode that focused quite a bit on another detective (“Tough Guys Don’t Die,” featuring Jerry Orbach, who then became an occasionally recurring character). The A Team overhauled the plot entirely and made it about special effects instead of newly created machines. This was a terrible failure (All of Season 5 featuring new team member Frankie Santana). The Incredible Hulk occasionally broke away from their formula and had an episode start with Dr. Banner already in Hulk form, so they didn’t have to do two transformations later (as the network required), and they also did an episode with Lou Ferrigno as a character who was NOT the Hulk, so everyone could see him with no makeup.
Really, the temptation is to go from one repetitive and formulaic solution to another. We need to be on our guard against that in the stories we write. I am fairly certain that this is one reason the Star Wars novels continue to be wildly popular – they keep bringing in fresh writers with fresh ideas. Where they used Timothy Zahn to re-launch in the 90s (and to reinvigorate a time or two since), they have also pulled in Kevin J. Anderson, Michael Stackpole, Aaron Allston, Troy Denning, Karen Traviss, Kathy Tyers, and literally dozens of other authors to bring new characters, new voices, and new plot devices to a series that has sold hundreds of millions of books (Allston, Stackpole, and Traviss are probably my favorite, but I only have ninety or so of the Star Wars novels, so I may not be qualified to judge this).
I think this is why any series I write will be relatively short. Yes, my first series is five books, but they tell one continuous story that I outlined before I began the first book. I don’t envision writing another series that long in the future as the later works take much longer to write (going back and ensuring consistency with earlier works is a painstakingly slow process).