OJ Simpson was originally supposed to be The Terminator. Pmsl.
The original concept for the time machine in the Back To The Future Trilogy was going to be fridge this then would seen Marty being sent back to the future via nuclear explosion in the desert. The idea was dropped by Steven Spielberg in fear of kids copying going into
a fridge so the DeLorean was used place it looked like the space ship that was on the comic that kid had in 1955 when Marty crashed into the Barn. The fridge idea was used again but in Indiana Jones 4.
In Terminator 2 where ever there was two Sarah Conners in certain scenes CGI wasn't actually used the double of Sarah Conner was actually played by Linda Hamilton identical twin sister.
R n B star Bobby Brown who sang the theme to Ghostbusters 2 "On Our Own" had a cameo in the movie he played the doorman for the major and asks for a proton pack for his kid brother. Also the scene at the end of Ghostbusters where Walter Peck at the end gets covered in marshmallow it actually was tons and tons of shaving cream.
Actor Alan Ritchson has was the voice of Raphael in 2014 Teenage Mutant Ninja Turtles Played Aqua Man in the TV show Smallville.
Henry Cavill was almost cast as Superman in Superman Returns.
Voice actor Peter Cullen the voice of Optimus Prime in the cartoons and movies voiced the Predator in all the movies.
There's a nod to Back To The Future in Terminator Genisys the truck that Sarah Conner is driving crashes into a DeLorean lol, also Robert Patrick the original T-1000 has a cameo in the film.
John Wick Director Chad Stahelski was Keanu Reeves' stunt double in The Matrix movies.
David Hayter who used to be the voice actor of Snake in the Metal Gear games was the scree writer for X-Men 1,2 and 3 and Watchmen.