Predator made for a good action flick... But Aliens :D
Look at those things! https://www.youtube.com/watch?v=kmDXVbte5Oc
I gotta go with predator.
Predators a just unstoppable. They have physical body strength, that complement their unparalleled technology. They kill Aliens for the hunt and thrill. Predators are just unstoppable.
Cause they are cooler and they don't put frekkin face huggers!
predator would win in my opinion because it can hunt monsters.