Aliens 1 & 2 were good. When I saw Alien 3 I thought "They can't POSSIBLY make a worse Alien movie" . . . and then they went and proved me wrong with Alien 4.
AvP was OK. Not brilliant, not horrid, but OK.
The problem, IMO, is that the Alien/Xenomorph is only truly dangerous in some very limited circumstances. For it to be dangerous again and again, people need to do amazingly stupid things . . .
Hear here - I'm really,
really beginning to hate movies, books, and TV shows where so many of the characters are, to put it bluntly, idiots, morons, and fools.
"We have to stick together - there's strength in numbers, and we'll watch each other's backs. Hey, Bubba, you go off by yourself, unarmed, into that dark & deserted part of the ship and see if you can find the cat, OK? Meanwhile, we're going to keep on our original path and put some distance between you and us."