Alien(s) The Movie. Predator movies. Alien Vs Predator movie(s).
When you boil it down.. Aren't they both technically 'alien'... Or even (the) Humans'... Outside of our home planet, Earth, are we not technically Alien?
My point... I think you would have to concede that, in the case of any - if not most - of those films, both sides/species/life-forms are technically Aliens. Depending on where they are any given moment.
Moreover, the 'Aliens' - the non 'Predator' titled aliens - Their purpose, at the very least, in most circumstances we see them in, is to hunt (they hunted Sigourney Weaver for like 85 sequels)... And literally, the label 'predator' is given to someone who does just that... Hunt, Prey.
Case and point. In the case of Aliens and Predators of the movies in the series' Alien, Aliens, Predator, Predator[ii]...etc, and Alien V Predator, Aliens V Predators....etc. Each or either are Alien and each or either are Predators.
Take that movie titles..
You're welcome.. Sleep now.. You can.