Killed while gaming? Just that one cock-eyed son-of-a-*****. But he was fixin aces up his sleaves.
Seriously, so many it becomes an exorcise in futility. I mean, where do I start counting? 100's hours of GALAXY? Lemmings? Playing Worms for days on end? Carmageddon? Tower Defence games also. Let alone zombie's, rts, tactical war sims, and my constant drive for a nuclear capability in any game that offers it (civ3....lets bomb paris...again)...ect.ect.ect. (are tetris blocks "enemies"?)
By my estimate, $0.00000000000000000000000000000000000000000024 a kill.