Thought it was really good, best to worst, here is my order of the films, and I am going by the longer/preferred versions of the films
1. Aliens - perfect, next to no flaws
2. Predator - perfect, same as above
3. Alien - near perfect, some minor pacing issues
4. AVP-R - very good, some minor flaws
5. Alien 3 - good, has flaws, but is a worthy sequel
6. Predator 2 - good, has flaws, but is a worthy sequel
7. AVP - average, has its moments, but not enough to make it good
8. A:R - average, has its moments, but not enough to make it good
Thats my whole take, those with the same descriptions aren't really in an order, I can't pick between Aliens and Predator or Alien 3 and Predator 2