Green Lantern Vs. Predator- Ron Marz and Rick Leonardi did a pretty sweet crossover involving both Hal Jordan's and Kyle Rayner's encounter with the Aliens back in 2000. Also eagle eyed readers who picked up the uber-event known as the
Sinestro Corps War, saw in one of the spalsh pages a Predator as a member of the Sinestro Corps. So a Pred fighting it out with Hal Jordan, John Stewart, Guy Gardener, or Kyle Rayner wouldn't be out of the question.
Jason Vs. Predator- I had an idea for a fan-fic involving a Predator coming to Crystal Lake, Ohio to hunt down Jason Voorhees. Only problem I ever really had with it is I didn't write it.