I can go one better than scratching a disk, my computer once blew up my copy of Yuri's Revenge. I was just playing a verses match against the computer when there was an enourmous bang from the computer and the game froze. I thought the computer had (violently) died, but I was able to quit to the desktop. I opened the CD drive the the CD itself poured out onto the floor; most of it was just dust, with a few larger fragments embeded inside the drive itself.
Half an hour with a screwdriver and pair of tweasers later, I'd gotten the biggest bits out of the drive and it was usable again, but the CD itself was way beyond any repair.
I was too shocked to be angry in the minutes after it happened, and by the time I realised I should be annoyed at my copy of the game being destroyed I was past the RARGH KILL stage.