I think it's pretty much a given that Jade is going to come back as a Black Lantern, because it'll provide some easy angst for Kyle and Alan and Todd. As interesting as I'm sure that'll be, I think the better mindf#%* resurrection for Kyle would be Alex DeWitt. In fact, Kyle fighting a tag-team of Alex and his mom might be one of the most morbidly awesome things ever.
Don't get me wrong, I love Kyle, and I don't want him to go all grim and gritty, but if we're going to have a story where the heroes have to battle the ghosts from their pasts, then we might as well go all-out, right?
John Stewart vs. The entire zombified population of Xanshi would be a close second, by the way.