My 'theory' on the Alien movies: All the movies reflect the characters of the original crew of the Nostromo.
Alien (1): the original movie that was original in many ways, even the way it was made. The 'making of' is a very good watch. This movie was like KANE (John Hurt) - it 'burst' onto the scene much like the Chest Bursting scene and we all had to 'take a look' in the Cinemas - just like Kane had to take a look inside that crashed Alien spaceship.
Aliens (2): This 'mass-slaughter' of Company military verses masses of Aliens after they wiped out a mass of human colonists is a 'shoot em up' effort. This reflects DALLAS (Tom Skerritt) who was the only 'military' assigned (Captain) of the Nostromo. Who also went into the air ducts to 'hunt down' the Alien with his flamethrower. Ripley also used a flamethrower in the Aliens movie.
Alien (3): Originally supposed to be a group of Monks, changed to criminals on a remote useless planet. All about the 'lowest' of Society, which BRETT (Harry Dean Stanton) was on the Crew. Thus he met his end in the 'dungeon' of the bowels of the Nostromo with the chains dangling. For those 'down there' who give up on hope.
Alien Resurrection (4): the most disliked movie of them all. It's about 'bio-engineering' (Ripley as a hybrid clone) and 'Androids' (Winona Ryder) and this brings the character of ASH (Ian Holm) into question on the original film and he betrays for Company orders.
AVP's (5) Aliens V Predators: These spin-off movies did well and kinda sum up PARKER (Yaphet Kotto). Big Predators with Dreadlocks give it that 'African' hunter feel and with Parker being the 'stand detached' token Black Man on the Nostromo crew that actually tries to physical take on the Alien.
Prometheus/Covenant (6): These movies sum up the character of LAMBERT ( Veronica Cartwright) and how the Company 'betrays' those who put their faith in it ("Liar" she yells at her death). Veronica received an Academy Award for her 'real' act of freaking out at the chest-bursting scene (because she was unaware of what was going to happen). I wouldn't be surprised if Covenant or its sequel gets an Award.
These are just slim pickings and I'm sure there are more 'coincidental' things associated with each one. But I'm pretty sure - that these movies are much like the characters of the original crew or a reflection of.
Which brings me to Alien (7) movie or movies that have to reflect the character of RIPLEY (Sigourney Weaver) herself.
The twist of this is that Ripley is the one character that doesn't die in the original movie - the Alien dies.
With a series that has been pushed by fans to continue on - will this truly be the 'End' of the Alien franchise? If so, it should go out with a blast.
I wonder if Sigourney Weaver would Direct it herself? Giving it that 'Ripley' flavour that the world came to admire of a very real 'female heroine' without far-fetched super powers.
The Alien movie and its following series of movies are a good watch and the original crew of characters were 'original' in their 'every day' normal people setting - flaws and all. The movies themselves have been much like.
So, will Alien 7 be just as amazing as the character of Ripley (after the next Covenant 2/Lambert movie is made)? Will the Aliens be gone for good?
The suspense is ...killing me!