9. The Irritating Disappearance of Judy Smith

In the early evening of April 10, 1997 panic set in when Jeffrey Smith realized his wife wasn't where she was supposed to be. Having flown to Philadelphia for a conference, Jeffrey and his wife Judy were to attend a cocktail party in their hotel after a day of sightseeing for Judy and moderating for Jeffrey. Jeffrey had no idea that morning was actually the last time he'd ever see Judy again.

5 months later the scattered remains of Judy's body were found 600 miles south at a campground in Asheville, NC. Her disappearance and murder remain a mystery to this day.

Shoutout to Wendy for researching this story as one of the "most irritating disappearance" due to the fact that it's wildly unusual and still unsolved.

Sources:

Reddit

Unsolved Mysteries

Wikipedia