To be sure, all of these have variations, but it's the same basic plot: a rather powerless nobody rises up to become a hero, an evil dark lord is sweeping across the world, hell bent on conquering it and only a single item, possessed by the hero can stop the tyrant. In some variations, the item is good and must be used (such as a sword). Of course, in the original LOTR plot, it had to be destroyed.
I even see this in the original Star Wars trilogy (particularly the one that started it all that that's now called "A New Hope"). An obscure farm boy comes into possession of two items: a droid with information that can be used to destroy the tyrant's world-destroying machine and a sword. He meets a wizard (Obi-Wan Kenobi). Even the cantina is reminiscent of the Prancing Pony. The hobbits met Strider, a roguish-seeming rough fellow who helps them get places they couldn't otherwise go and get past the forces of evil (in this case the Black Riders). Luke meets Han Solo: a roguish-seeming rough fellow who helps him get places he couldn't otherwise go and get past the forces of evil (in this case the Star Destroyers).
To be sure, people can point out plots that influenced LOTR. Some of these plots are, of course, as old as the hills. Yet, Tom Shippey, one of Tolkien's graduate students, said that he thought what both distinguished LOTR from its imitators and made it modern, as opposed to something like Beowulf which definitely influenced it, is that Frodo is just an ordinary person. He has no more power than any of us. And, he never gets extra power. He isn't the "Chosen One", "The One" or "the Seeker". He doesn't receive Jedi training. Although he is given a magic sword by his uncle, it doesn't make him powerful enough to take on the forces of evil in direct confrontation. It allows him to kill Shelob, but that's it. What I mean is that it doesn't transform him into a super-human hero.
Moreover, even the larger-than-life heroes like Aragorn and Gandalf are still less powerful than the Sauron. The armies of good are still inferior to the armies of evil.
What this means is that Frodo has to accomplish his quest with more-or-less the same level of power we all possess. I mean, yes, he has the help of a magic dagger, dwarven chain mail and the like. But, then, we are not faced with giant spiders and orc chieftains in our lives. Throughout the epic, Frodo remains lower-power compared to not only the forces of evil but many of the good heroes. And, yet again, he wins through where they would not have because Sauron overlooks him.
That brings me to the real point of this entry. I'm just beginning to contemplate why the LOTR plot is so pervasive in the popular psyche. I think it's more than just a good story. Good stories can get imitated, but imitation does not even begin to describe what's happened to it. It's more like it's the epicenter of an explosion in the story consciousness of the modern world.
Why? The only reason I've come up with so far is that Frodo is just one of us. We all have the same abilities as him (well, okay, apart from the magic dagger and Dwarven mail -- but then we all find other helpful things along the ways of our lives too). We can all do what Frodo did and stand the same chance of success. I find that inspiring. Would that we could all have the courage, the fortitude and the inner strength of Frodo Baggins. I hope that we all keep putting our little feet in front of each other and march, however hopelessly it may seem, toward saving our world.
What does that mean? Maybe something different for each of us, but something equally valid for each of us.