I think a Colonial Marines TV Series could work...
Just if Fans would accept that maybe it does-not have to be about Bug Hunts, well Xenomorphs! The Colonial Marines have surely done more than just KILLING those Aliens and getting Killed in Return in ALIEN.
You have to look at other Reasons for such a Military Contingent, and remember the Xenomorph was just ANOTHER Bug Hunt... so they have been involved in tackling other Alien Pests.. that are Unrelated to Xenomorphs.
Rogue/Awol Synthetics have been shown in the Franchise, so the Colonial Marines could be shown to deal with such a Threat in another Episode.
You could follow a Team of Colonial Marines from Training EP1-3 to then some Missions with various threats.. of the Synthetic Kind, Human Kind and Alien Pest Kind... even have a Episode showing some Down Time in-between Missions, where we could see what was all the Fuss about those Arcturian Poontang
The Final Episode could be to deal with something thats related from events of the ALIEN Franchise/Prequels.. be that Black Goo Related, or Xenomorph Egg Related. This would be the Climax Episode or TWO
A Hadleys Hope TV Series i think would be limited, because its would Fans be interested in the Day to Day Life of the Colonist... they would have to be some Action, Thriller and Conspiracy. I think it COULD work if its a Short Series.
So say 4 x 45 Minutes or 2 X 90 or 3 x Hour for example.. or maybe more but i think you would only need 4 hours to cover such a TV Series... which has to end with the First Outbreak of Xenomorphs.
I think a Prometheus Series would depend upon WHAT aspect to we follow from this? Events leading to the Mission, Events after the Loss of the Mission?
Engineers, but in the Past! This could get a bit Star Gate though!
We could consider a CAPRICA/BATTLE STAR GALACTICA
By that the Galaxy is Large... and can we assume that Earth is the only place where Humans are, in context to other Worlds the Engineers have Human Colonies and Interact.
So we could go to another Place in the Galaxy with Humans or very similar, and while yes to start with we can have them use a Alien/Ancient Dialect with Subtitles, then have them speaking English so we get the idea they dont speak English but its just for our Convenience.
You could explore in Flash Backs the Engineers reasons for Creation, and even indicate times they visited Earth, and maybe reasons we was abandoned?
Our Creation seemed to be something of importance and a lot of Effort, and it was indicated our Engineers are never just about Create Mankind and Create Xenomorphs. We all remember the Space Jesus... well that the Engineers had tried to send a Emissary to put us on track and we killed him and THAT was the LAST STRAW..
In the Bible GOD has had his fair share of Run ins and Punishment towards Mankind who he deems to being going against his Wishes! The Engineers intended to use the BLACK GOO... but GOD had used the Flood/Deluge!
However... God did at one time have High Hopes for his Creation and saw they can Redeem themselves and HENCE he got NOAH to create the Arc... instead of just KILLING all Mankind and having to Start-Again!
We can ask would the Engineers NOT consider doing the same? Or maybe some Engineers took pity and decided to take some Humans to another place FAR FAR away where the Engineers can Interact with these and give them a 2nd Chance and learn from the Mistakes that caused Mankind to behave in ways that UPSET them.
So you could explore such a Expanded Universe...
You could even at latter point introduce some incoming Humans from Earth, and what this could do as far as the other Humans who had been raised to NOT be as Corrupt as Mankind on Earth.
Or after the events of Planet 4, some returning Engineers Discover what happened, and they then go "right off we go to other Human Colonies and WIPE them all out, its the only way to be sure"
So you have some Engineers arrive at this World where Humans and Engineers are in Harmony, and want to Destroy those Humans as a Precaution against Rebellion.
You could then see those Engineers on this World, stand up against this Plot, and a Conflict Arises... which then leads those Humans to ASK what the hell was all that about!
Which is when these Engineers can reveal to the Humans their True Origins, and about WHY the Engineers then decided to UNDO certain Creations... which could give indication to the Process of the Death Camps well the Outposts to Create such Deadly Biological Warfare.
So these Humans who may have believed they are alone, with their Engineer Guardians then Discover that there is a whole Galaxy of Creations/Humans... and maybe they then want to SET-OFF and explore!
Even as far as coming to Earth after the Events of Alien Resurrection and Discovering that Mankind really had turned their Paradise into a Hell Hole!
so yes via this we could get answers to some of those Questions that Dr Shaw would have had... and indeed we can open up the Franchise to STAR-TREK levels.
I mention this because THIS is what i was going to cover with my Prometheus 3 as far as WHERE it was that David and Dr Shaw end up.... which is a World inhabited by Humans Many Thousands of Light Years from Earth!
A World that would take Human Ships circa 2100-2120 Hundreds of Years to Reach even if they had the Directions.. but a Journey that is VASTLY less for Engineer Ships.