I'm sorry but I disagree with all of you. I hate the idea of a dark ride based around all ride stories. The backstory and theme is what makes a ride unique. Placing them all in one would be horrible and I'd hate it.
However a dark ride in the Dark Forest would be good like Dinosaur at AK. It could be you enter a graveyard in search of the missing Th13teen girl. However you meet wraiths along the way and there could be parts related to Rita as well.
Or what I would really love is a dinosaur type ride in FV themed to the Nemesis monster. You're on a hunt for an egg but hit trouble along the way. It would be exactly the same story as N:ST, however I know this would never happen