Matt at X-Entertainment, my online retro god, has a fabulous list of seven moments from "Unsolved Mysteries" that scared the crap out of him.
I remember this show! In the days before there were entire channels devoted to true-crime, it was novel and pretty eerie. Can't say I remember any of the cases Matt recounts, but they're spooky and he provides updates where he can. Not a lot of these cases were ever moved from the Unsolved Mysteries drawer to the Solved one, it seems.