Here, I'll start. When I was 8 years old, my parents went to a dinner party and plonked me down in front of the host's computer so I'd stay out of their way. The game they booted up to keep me occupied was Space Quest II. Little did they know what impact that would have on me...
The first adventure game I played was Lesuire Suite Larry, my bigger brothers had savegames in all the interesting parts and I didn't knew English so I accidentally deleted all the saves trying to load them, needles to say I was banned from the PC for a long time. The one that really hooked me on the genre though was The Curse of Monkey Island.