The glitched Hall of Fame in Pokemon...
For those unaware, in the original Pokemon Red/Blue there was the glitch Pokemon called MissingNo. If you saw it, one of the side-effects was that your Hall of Fame data not only became corrupted, but the music in it became distorted.
Now imagine you're about 10 years old and you look at it expecting to see your old team, and are instead greeted by monsters that aren't yours with names made up of various glitched symbols, and what sound like the 8 bit screams of the dead.