I agree with you on Alien movies. Love the first two, and I actually love the 3rd too. But the problem I had with it was that it was just Alien, but with a different cast and location. And the disappointment I had with that was the fact that they had so many big and well known actors in it.
Resurrection was endemic of Joss Whedon - who wrote the screen play. A bit quirky, and sometimes a bit difficult to take seriously. But the concept was awesome IMO.
I only read a couple of the AvP cross-overs, where it's not pure AvP - mixed in with Batman or Terminator etc etc. They were good, if not a little directed to make the protagonists seem like God. But they weren't bad reads. I did however play the original PC games.
AvP had potencial as a film, but they squandered it with a restrictive plot and characters. And tried to explain too much in a short space of time. If made now, you could almost guarantee it would be a 2 or 3 part series.