Leeroy Jenkins - World of Warcraft
Okay, so it was fake. But who remembers when this video first arrived on the internet? It wasn't about being fake or not, nor was it really specific to World of Warcraft. When you play with anonymous folks in a video game, you're bound to have at least one person that's just a little 'different'. The video went viral and Blizzard loved it so much they added him to their desktop card game, Hearthstone and as in the Warlords of Draenor expansion as a garrison follower.