Ty for the cayleigh elise back up channel!Rob Gavagan's Seriously Strange: Not all of his videos are about unsolved creepy mysteries, but a good chunk of them are.
Cayleigh Elise: Before she deleted her channel upon getting a new job, she was where I primarily learned about missing people, unsolved murders, and unidentified John and Jane Does. Fortunately, a channel has currently uploaded all her old content, and as of the writing of this post, all of it is available for viewing.
Unsolved Mysteries: The one that started it all, and they've fortunately uploaded all of their old episodes onto Youtube for free. There's also a reboot coming to Netflix this year, something I honestly can't wait for.