I know I wasn't the target audience, but I always liked Amethyst, Princess of Gemworld. The first mini-series was great. The resulting series was a little weaker, and when the creative team changed post-Crisis, it kind of went off the rails. Still, those first twelve issues are solid entertainment.
I'm surprised DC hasn't done more with it. I think I slightly retooled version would be a bang-up Johnny DC project, and a trade, maybe at manga size, would do pretty well too. Heck, in these days of Chronicles of Narnia and Lord of the Rings, I'd think a movie or TV mini-series would be possible, too. I remember that DC was thinking of doing an animated cartoon back in the late eighties. I wonder what ever happened to that.