A year or so on after Gary Gygax, Dave Arneson, coauthor of Dungeons & Dragons has died (Ars Technica: Between battles, the story: Dave Arneson has passed on).  Dungeons and Dragons (and subsequently several other roleplaying games) played a hugeand very important part in my life from my teens into my late 20s. 

Arneson had some sort of falling out with Gary Gygax and left TSR (the publishers of D&D) in 1975, but apparently he was at least partially back in the fold for the third edition of the game.  The Ars Technica review says it better than I can.