Take your favorite parts from each movie - your ultimate movie A/P or AVPR

[Dan2004]

Cant go wild, try to keep it basic but meaningful. Each part will form your own NEW movie 

Alien: Discovering the eggs & general ship environment
Aliens: Power Loader (Queen Scene)
Alien 3: Dog Alien variant
Resurrection: Escaping the holding room/cell (Aliens)
Prometheus: David
Covenant: Engineer world and releasing the pathogen
Romulus: Capturing and the escaping Big Chap
Predator: Dutch
Predator 2: The ship and various predators
AVP: Scar killing the Alien on the wall
AVP-R: Wolf, notably the underground tunnel scene
The Predator: NOTHING
Predators: Falconer Predator
Prey: Interacting with the Bear and Wolf, generally killing other life forms

[Xenotaris]

Alien: Xenomorph getting the drop on Dallas and the Eggmorphing deleted scene
Aliens: The xenomorphs hiding in the ceiling and the Power Loader vs Queen scene
Alien 3: The Runner's jaws cover in human blood, very chilling.
Resurrection: The xenomorphs swimming underwater
Prometheus: the alternate Fifield and the Engineer holograms running down the corridor
Covenant: the praetomorph/protomorph/planet 4 xenomorph attacking the lander.
Romulus: the fighting the xenomorphs in zero G scene
Predator: Predator unmask
Predator 2: Smartdisk scene
AVP: End Credits
AVP-R: WOLF
Predators: Hanzo vs Falconer
The Predator: End Credits
Prey: Bear vs Feral

[Dan2004]

Alien: Xenomorph getting the drop on Dallas and the Eggmorphing deleted scene
Aliens: The xenomorphs hiding in the ceiling and the Power Loader vs Queen scene
Alien 3: The Runner's jaws cover in human blood, very chilling.
Resurrection: The xenomorphs swimming underwater
Prometheus: the alternate Fifield and the Engineer holograms running down the corridor
Covenant: the praetomorph/protomorph/planet 4 xenomorph attacking the lander.
Romulus: the fighting the xenomorphs in zero G scene
Predator: Predator unmask
Predator 2: Smartdisk scene
AVP: End Credits
AVP-R: WOLF
Predators: Hanzo vs Falconer
The Predator: End Credits
Prey: Bear vs Feral

The end credits.... Love that 

[Xenotaris]

Yeah, lol.

[DiabloGuapo]

Alien: The air vent scene. 
Aliens: Memorable USCM characters.
Predator: The tough, overly confident soldiers becoming the hunted.
Predator 2: Introducing more Yautja weapons and lore.
Alien 3: A fast and ruthless Xenomorph.
Alien Resurrection: The Xenomorph breakout.
AvP: A good balance between the number of Xenomorphs and Yautja and not favoring one side too much.
AvP-R: The National Guard being slaughtered by the Xenomorphs.
Predators: Yautja with different specialties.
Prometheus: The Anathema.
Alien Covenant: The Praetomorph loose on the Covenant.   
The Predator: The Yautja breakout from the lab.
Prey: Yautja fighting the bear.
Alien Romulus: The Facehugger chase scene.

[Pulser]

Alien: The air vent scene.

Yup, The horror exists in that scene.

[solace97]

Alien - too many to choose from but the entire ending sequence is so perfectly executed once it's only Ripley left and you hear lambert scream
Aliens - the operations scene before the aliens plop from the ceiling
Alien 3 - I always liked Dillon's speech and when the alien passes on Ripley
Alien Rez- aliens escaping
Prometheus - the opening sequence and the space travel scenes are cinematically beautiful
Covenant - neomorph and spores
Rommy - alien cocoon scene
Predator - any scene with the Predator stalking and them not knowing wtf it is
Predator 2 - spaceship scene and king Willy
Predators - classic vs berserker and the hounds and the Japanese vs falconer
The Predator - the escape scene
Prey - feral chasing naru through the grass and killing the first group of Indians 
Predator killer of killers - the Japan based one was cool
Avp - the premise of the predators capturing a queen and having those pyramids was cool as well as the alien killing chopper
AVPR - for what little we saw I actually liked the Predators in the beginning that the predalien kills and the inside of the ship with all the xenomorph stuff in there as well as wolf's lair