[adamsb6]

Even more terrifying for the uninitiated back in the day: fatal error

[z500]

Reminds me of getting the "illegal operation" error from Windows when I was a little kid and wondering if I just committed a crime.

[cj]

Window's blue screen of death (full of cryptic error codes), for those old enough to remember!

Edit: Is the blue screen of death still a thing these days? I haven't actually used Windows in a decade.

[joombaga]

Yes, though the color varies by release and build channel. The current GA release has B(lack)S(s)oD.