Red Shirt Guy
Red Shirt Guy appeared at a World of Warcraft Lore Q&A panel at Blizzcon 2010, and skewered Chris Metzen with a question about an discontinuity in character naming from the WoW lore.
The questioner's halting delivery and utterly-earnest nature, as well as the triumph of his question, turned him into an instant internet legend. We can only hope that the Diablo III story and lore inspires such attention to detail, and that vigilant eyes keep the writers from engaging in too much creative retconning.
Here's Red Shirt Guy in action, from Blizzcon 2010.