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 one I played was Les Manley Search For The King. I was around 8 and we got it from a family friend who gave us a box full of floppies. I remember being amazed and thinking "you can do anything in this game".
I later discovered it was a sorta ripoff of Leisure Suit Larry, but in my opinion a better game.
I've yet to play those. I played Rex Nebular, the "Leisure Suit Larry in space," and it was... not good. I have half a mind to do a very scathing video about it at some point.