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...
I didn't play that until 18 when I bought the King's Quest collection. I think if that had been my first experience, I wouldn't have ventured into the adventure games world at all.
Somehow my friend from school had gotten wind of the "bye bye wizard" cheat code, and we STILL couldn't get anywhere in the game. I'll take falling off a space station to my death, thanks. ๐