THe Aliens franchise is far superior to the Predator...although...they're both legends in their own right.
As for who is a superior killer? That depends...having a one on one fight with an Alien vs. a Predator is kind of unfair, as the true strength of the Alien is the same as that of the Zerg, and the Russian army, highly expendable due to massive numbers.
Now taking technology out of the predators hand it can be a tough match, and they seem to be relatively even match...and an alien can take out a fully geared predator if it has the element of surprise (which is how they kill US so damn easily, but it's harder to surprise a Predator).
also, AvP the movie was awful (the two games are amazing), and AvPR is good, I thoroughly enjoyed it...but...it doesn't live up to the standards set by it's namesakes.
As for who is a superior killer? That depends...having a one on one fight with an Alien vs. a Predator is kind of unfair, as the true strength of the Alien is the same as that of the Zerg, and the Russian army, highly expendable due to massive numbers.
Now taking technology out of the predators hand it can be a tough match, and they seem to be relatively even match...and an alien can take out a fully geared predator if it has the element of surprise (which is how they kill US so damn easily, but it's harder to surprise a Predator).
also, AvP the movie was awful (the two games are amazing), and AvPR is good, I thoroughly enjoyed it...but...it doesn't live up to the standards set by it's namesakes.