I read all the posts in the thread. Interesting.
For me the choice is easy. Option one
Unlike some people here, I enjoy all six Alien franchise movies enough that I would be fine with watching any of them again.
Also, the poll has the movies in timeline chronological order. It would be natural for me to watch the prequels and then "Alien".
And after that, I would watch the next trilogy.
Observations about the thread; some people consider "Alien 3" an excellent movie far above the prequels. I don't. I prefer "Prometheus" more than A3.
I saw A3 in a theater at release and was disappointed. The assembly cut doesn't fix the main weaknesses I have. And Fincher isn't coming back to do a director's cut. I don't want to get into more details because there is a separate thread about A3.
There is a large time gap between "Covenant" and "Alien" but there is also a significant time gap between A3 and "Alien Resurrection". Not a problem imo.
Also, someone pointed out that the six films have genetic manipulation at the beginning and at the end. True. Some of the things that the Engineers were doing in Pro were being done by human scientists in AR which creates a bit of unity in the entire story. The Dr. Frankenstein/ scientists playing God trope which goes back to the beginning of science-fiction.