1995
In the "coming attractions" section of the April 1995 issue, a Sonic the Hedgehog game (a character created by Sega exclusive to their console at the time) was listed as being published by "Nintendo". Donald Kenney from North Tonawanda, NY wrote into EGM finding the error, which turned out to be intentional as 1995's EGM April Fools Joke.
Read more about this topic: EGM April Fools' Jokes