Ok, maybe conspiracy isn't the best word for it. But have you had a talk, between you and a gaming friend, talking about what you think a certain plotpoint really meant, or who do you think said masked character really is and why he is doing what they are doing? or even when you remember back in the day when there wasnt the internet and you and your friends passed around info like "If you beat Arcade mode within 5 minutes, without getting hit and only using this move, you will unlock ......" and etc... those types of things.
One of the main ones I can think of is the Mew being underneath the truck at the harbor where the SS Anne is in Pokemon Red and Blue.
Another one being, since I'm a fan of the series, the consensus that Nero's Devil Trigger from DMC4, is actually Vergil's spirit. Some keypoints supporting that, are Nero saying how once he got his arm, a voice in his head started craving for "more power" (one of Vergil's main lines and ambitions in DMC3), it's ability to fix Yamato (Vergil's Devil Arm/Sword), and a striking resemblance in Devil Trigger appearance (mainly, the horns of Nelo Angelo, and the arm sheath from Vergil's Devil Trigger).
So, please, tell us about some of your theories and false facts you've heard about video games over the years.
The Mew truck in Pokemon. What a mean trick. I really wanted a Mew at the time.