Not truly "classic gaming," but this fits with the topic and I love to tell and hate this story.

I had Gran Turismo 3 for PS2 and I played over 150 hours. I had unlocked just about everything, and was mildly obsessed with the game for a while.

My freshman year of college this was, and a friend in the dorm asked to borrow my PS2 for some WWF wrestling game he rented.

When I got my system back the next day there were about 30 created wrestlers on my memory card. In order to fit all of those wrestlers he needed to clear space... BY ERASING MY GRAN TURISMO 3 SAVE!!

I have not touched a game in the series since and am bitter to this day.