Not sold and regretted. But in my youth, my brothers and myself were not great at taking care of games, so we'd change discs and just leave games sit out on tables or whatever. We've lost many a good game to poor handling. The highlights of such poor handling would be:
Megaman X (SNES) (Have other iterations of it)
Digimon World (PS1) (Still looking to acquire another)
Digimon World 2 (PS1) (Recently acquired anew)
Castlevania: Symphony of the Night (PS1) (Still sorta works, but not consistently)
Finall Fantasy VII (PS1) (Have acquired a few copies since then)