I know you already made a whole video about Resident Evil facts but I figured a bunch more wouldn't hurt
I do have quite a bunch, so bear with me. Even dug out some sources to prove my facts. Some of them weren't exactly easy to find...
The games' original Japanese name Biohazard got changed because trademarking "Biohazard" would have been too difficult, mainly because of a DOS game and a band of the same name. The name Resident Evil came from a naming contest held within the company.
http://kotaku.com/5204463/why-was-biohaz...ident-evil
Leon was originally supposed to have a basset hound as a pet dog.
http://images1.wikia.nocookie.net/__cb20...is_Dog.jpg
In the Sega Saturn version the Hunter Alpha's of the original game were replaced by a variant called Tick, which was a somewhat insectoid looking Hunter with its sickle arms and antennae.
http://www.youtube.com/watch?v=Baxgz8EPhcU
Robert Kendo's brother, Joe Kendo, is hinted to be still alive as the words "Kendo Gun Shop" have been engraved in Leon's gun, the Silver Ghost, in RE4.
http://images.wikia.com/residentevil/ima...ail%29.jpg
You can find a post-it note describing a recipe for a "Jill Sandwich" near an RPD office desk in Resident Evil Uprising, the mobile version of RE2.
http://i55.tinypic.com/2wg4o6d.png
Leon was originally supposed to be rescuing Sherry Birkin in RE4 and the story was supposed to tie in with what Wesker said in Wesker's Report: "Sherry is safe in our hands". That part was, however, removed from both the game and the 10th anniversary edition of Wesker's Report.
http://www.relyonhorror.com/in-depth/res...-analysis/ (Check the Diary of a Madman part)
The cast to the original Resident Evil was supposed to compose of Jill and Chris but also two characters called Dewey (the team's african-american medic) and Geltzer (the team's huge radio operative). Dewey was planned as a comic relief and the name was later used for the STARS pilot.
http://www.unseen64.net/wp-content/uploa...oncept.jpg
Resident Evil was actually born from a project to create a successor to Capcom's Famicom game Sweet Home, which in turn was based on a movie of the same name.
http://www.residentevilforums.net/t2535-...-all-began
Nemesis (RE3), Thanatos (Outbreak), Hypnos (Survivor) and Nyx (Outbreak File#2) are all named after ancient Greek deities.
George A. Romero was originally attached to writing/directing the live action films but eventually the project was given to Paul W.S. Anderson. Romero had previously made the live action trailer for RE2.
http://www.dailyscript.com/scripts/resid...omero.html &
http://www.youtube.com/watch?v=5vSlRrL689Y
There is a fast food restaurant called Jill's Sandwiches found in the original Dead Rising.
http://dead-rising.wikia.com/wiki/Jill%27s_Sandwiches
Now, here are some interesting RE5 concept facts:
http://www.relyonhorror.com/in-depth/res...-concepts/
While the game was originally not supposed to be a co-op experience, Chris still had a partner to go with him in Africa and Sheva still existed in the game. Chris' original partner was Barry and Sheva was going to be a part of local militia fighting against the BOWs.
Excella was originally supposed to be killed by a tyrant, similar to what happened to Albert Wesker in the original game.
Parts of RE5 Beta were later used in RE6. Mainly the underground ruins with parts being under water, Gigante-like giants assaulting a town while you had to protect another character trying to device help and a boss battle fought on a train where you had to run from car to car while fighting it. The monster itself (Irving) was very similar to Birkin's final form.