Did you know that Alien 3 was originally supposed to take place on a planet made entirely of wood? Yeah, a wood planet. I swear, I'm not making this stuff up.
I still consider Alien and Aliens to be among some of the greatest sci-fi horror/action films ever made.
Ridley Scott's Alien was a masterpiece of sci-fi horror. It did just about everything right. So much so that it still influences sci-fi and horror films to this day.
James Cameron's sequel, Aliens, wasn't as surprising as the original, but the direction he took the story and the universe was brilliant. It was the perfect way to expand the story while staying true to the original. (without being stifled)
Alien 3 had some interesting ideas, but failed in it's execution in just about every way. At best, it was mediocre. And, even that's being kind.
Resurrection was an abomination. It took the barest minimum of themes from the first two films and added in the most basic forms of sci-fi tropes they could think of. Quirky, goofy, "buddy" mercs. Cloning. Secret labs working on something "dangerous". A half-hearted attempt at being contemplative on the topic of the rights of artificial intelligence.
In short, it was awful. Just awful. Especially that exceedingly out-of-place, awkward third reel. (guh, that final death scene. *shiver*)
The only "alien" film(s) that could possibly be considered worse that Resurrection would be the two Alien vs. Predator films. Those were...were...
Never mind. I don't even want to think about them. They were an occasion of a franchise that not only jumped the shark, but picked up the shark to beat a dead horse with it.