Predators was just too dreary and sad. They start out giving the protagonists "no hope", and they are revealed to be killers so you have some token of relief to accept this, that maybe they deserve this fate, but the predators are just powerful enough without making them into kidnappers and executioners and judges like this. The movie develops some new concepts like the alien dogs that are interesting, but the super predators are overkill again, and their blood-fued is hardly developed so it isn't really worth putting in the movie. There is one lackluster fight between a predator and a super predator, and the rest of the movie is a harsh, dead-serious fight for survival against some of the most insane odds ever put in a movie. I liked the performances and the characters, though, and give this film 2.5 stars out of four.
I give Predator 1 four stars, Predator 2, two and a half stars, AVP two and a half stars, and AVP2 one and a half stars.