My collection includes:
Alien (1979) VHS, DVD, PSP, and Blu-ray (including Director's Cut and 40th Anniversary Edition)
Aliens (1986) VHS, DVD, and Blu-ray (including Special Edition)
Predator (1987) VHS, DVD, PSP, and Blu-ray (including Special Edition)
Predator 2 (1990) VHS, DVD and Blu-ray (including Special Edition)
Alien 3 (1992) VHS, DVD, and Blu-ray (including Special Edition)
Alien Resurrection (1997) VHS, DVD, and Blu-ray (including Special Edition)
Alien vs. Predator (2004) VHS, DVD, PSP, and Blu-ray (including Special Edition)
Aliens vs. Predator: Requiem (2007) DVD and Blu-ray (including Special Edition)
Predators (2010) DVD and Blu-ray (including Steelbook)
Prometheus (2012) DVD and Blu-ray (including Steelbook and 4-Disc Collector's Edition)
Alien: Covenant (2017) DVD and Blu-ray (including Steelbook)
The Predator (2018) DVD and Blu-ray (including Steelbook)
Also including boxsets:
Alien Saga VHS Boxset
The Alien Legacy - 20th Anniversary Edition DVD Boxset
Alien Legacy - 20th Anniversary Edition DVD Boxset (second version)
Alien Quadrilogy DVD Boxset
Predator - Special Edition Collection DVD Boxset
Alien vs. Predator - Limited Edition Collectible DVD Gift Set
Aliens vs. Predator: Requiem - Extended Edition DVD Box Set
Alien/Predator - Total Destruction: The Ultimate DVD Collection
Alien/Predator - Total Destruction Collection DVD Boxset
Alien Collection DVD Boxset
Alien Collection - Box Collection DVD Boxset
Predator Trilogy DVD Boxset
Alien/AVP/Predator - The Ultimate Annihilation: Nine Movie Collection/The Ultimate Blu-ray Collection
Prometheus to Alien: The Evolution Blu-ray Boxset
Alien Anthology - Sideshow Collectibles Egg Limited Edition Blu-ray Boxset
Alien Anthology Blu-ray Boxset
Predator 2-Pack Blu-ray Boxset
AVP 1&2 Collector's Blu-ray Boxset
Predator Collection Blu-ray Boxset
AVP 2-Film DVD and Blu-ray Boxset
Prometheus/Covenant 2-Film DVD and Blu-ray Boxset
Alien - 6-Film Collection DVD and Blu-ray Boxset
Predator Quadrilogy DVD and Blu-ray Boxset
That's about it!