When I was younger, I used to pretend Disney's Three Musketeers rolls right into The Man in the Iron Mask.
The old Zorro TV show, I consider canon for the Antonio Banderas movies.
I think I even tried to reconcile Sword in the Stone with Excalibur as a kid.
The Scream franchise, IKWYDLS franchise and View Askewniverse exist in the same cinematic universe for me and not just because of the Jay and Silent Bob cameo.
I do like the Wall-E leads to A Bug's Life theory.
Snatch. Lock Stock, Hackers and Trainspotting, El Mariachi Trilogy, Blow and Casino are all in the same universe to me.
I consider Halloween 4-6 part of the real Halloween continuity. Rob Zombie's two and III don't exist, and H20 and H11 are Elseworlds.
Bates Motel minus the last season and Psycho are the same universe.
All the Herbie films are in continuity/same universe. Both the Love Boat made for TV one and Lindsey Lohan's. The TV show too.
Mighty Ducks films, Airborne, Little Giants, Ladybugs, the first four Karate Kid films, Only the Strong, and the KO Karate Kid with Billy Banks, all those wolf movies (White Wolf, etc. that had all those 90s teen actors from Kids Incorporated, 90210, Saved by the Bell, other stuff) are all the same universe.
Total Recall, Lost in Space and the Burton Planet of the Apes are the same universe.
All the Grisham novel films, Jack Ryan films, and Alex Cross films are the same universe.
I secretly imagine the Ocean's Eleven trilogy and Fast and Furious franchises coexist and that Danny Ocean and crew look down on the others' crude antics. I also imagine the UK show Hustle in the same world.