For me the question wasn't even fair, the first 1979 version is the best Alien movie. I like the haunting atmosphere of the first film, the horror elements, the theme changes, the development of the actors' characters as the story progresses, the details, etc. Otherwise, the film is exceptional in the world of cinema.
Aliens comes in second, but it's hard to compare Cameron and Scott's films because they represent different film genres.
James Cameron's Aliens movie has a strong action and hero vibe right from the beginning, lots of guns, macho action, lots of aliens, lots of everything...compared to Ridley Scott's Alien movie, I think Cameron's Aliens has too much of everything.
Alien 3 was a good try, but is overshadowed by the first two Alien movies.
What about Alien Resurrection...that's a movie that shouldn't have been made at all.
"David8" movies have been less noticed by me. Sure, they're well done and everything is ok, but...there is something about them that I don't like, I don't know what, maybe it's the plot and xeno birth idea that I don't really like - I can't say.
I'm waiting to see a Romulus movie, but I think it's just a teen slasher movie in space without any major plot content or more aliens in the story.
I expect more from the TV Series than from Romulus.