Pitting Aliens and/or Predators against superheroes is (more often than not) pretty lame. Putting the Aliens and/or Predators in other sci-fi/horror franchises, though, would be pretty cool. For example, Aliens vs. Predator vs. Mimic would have some interesting possibilities, as would the Aliens showing up in the Blade Runner and Stargate universes. Also, putting Aliens and Predators in the Star Trek universe (say, Klingons vs. Predator) would be pretty fun, if for no other reason than to see our favorite ETs kick the snot out of a few Starfleet officers.