Something I'd actually like to return to one day, even though I don't think I've touched it in 10-12 years (presuming the date stamps on the Word files can be believed), is a story that's sort of the opposite of most fantasy quest plots. Instead of the heroine being whisked off to a magical land, etc., this time the heroine is from a magical land, and gets whisked off here instead.
A quick and dirty recap: Gwynn's father is the king, and his realm is all but conquered by the forces of evil. In desperation he has his wizard carry off his children to safety, but he only has time to take her to the nearest available port, which ends up being here. From there the story becomes seemingly pedestrian, with her surviving here and meeting a boy she likes, while at the same time discovering she's a wizard too. And realizing the forces that defeated her father are still searching for her.
The interesting thing about that one, is that I had originally conceived of it as a screenplay, since most of the visuals and plotlets in my head are really light on the narration, like the scene of Gwynn and her boyfriend being chased by a dragon -- on his motorcycle, down Storrow Drive, in Boston. It'll make a great scene in the movie.
For once, I only ever imagined it requiring a single book, and I do have quite a bit of the plot and more than a few scenes ready to go in my head, so I could jump back into it fairly easily, if desire strikes firmly enough. As always, I would probably have to re-write the 6 brief chapters that already exist (Chapter 1 word count: 3575 words; New Thing chapter 1: 5130 words; Magnum Opus chapter 1: 11,043 words). But I did that with the NT, and as always, it's better now, so that would likely turn out just fine.