Lost Media that lived up to the hype

Clockman. Its a very creepy short between the choppy animation, strange character designs, abduction and the last line ("not all stories of lost gloves end so well" as the clockman watches Sally with a malevolent grin.) Its not exactly the Texas Chainsaw Massacre but there is definitely a grim veneer around it. I could absolutely imagine myself getting scared by it as a kid, and even as an adult it creeps me out a little. (I enjoy watching it tho, its also charming.)

Clockman doesnt deserve to be mentioned in the same breath as Cracks or Cry Baby Lane, which arent frightening at all.

Yeah I'm inclined to agree with you here. Again, Clockman isn't terrifying, but there is something rather unsettling about it.
I wonder if that has to do with the European origins of the short. Children's stories and fairy tales in Europe come from a more grim and unsettling tradition than in the States (especially Central/Eastern Europe), so that may reflect in how that story was made.
When I was a kid, there was a short animation that used to creep me out called "Teeny Tiny" and the Witch Woman. I would argue that it still has that creepy vibe today:

www.youtube.com/watch?v=M2Hq4AzOhds

I don't really have any examples of lost media that ended up being as unsettling as the hype surrounding it, I have a lot of general lost media searches that were worth the effort (and some that weren't).

For one, the Kappa Mikey MTV pilot was one of my favorite searches ever. Ever since I read the article that claimed a more adult version of the kid-friendly Nicktoon existed, I had to see what that was all about. I have so many fond memories from that search- being up at 2 or 3am searching the internet for names of crew members (and trying to find their contact info), the disappointment when contacts would get back to me saying they didn't have it or never even heard of it, and the sliver of hope when the occasional "oh yeah I've heard of that, Larry Schwarz showed it to us one day during lunch". I knew someone from production had to have it, and 8 months later the director came through for me and uploaded it. It was mostly everything I was expecting it would be, which was really cool. I think I would have preferred a little more adult humor or some stronger language for a stronger juxtaposition to the show, but all in all I was so happy that all my effort paid off. That was the search that really cemented my interest in lost media and gave me a lot of the foundation I now use when I search for lost things.

On the contrary (and I guess this more directly relates to the thread topic, albeit in the opposite way lol), I would say within recent memory the search for The Wire short from Toonheads ended up being a little disappointing. The original post described it as this eerie short seen late at night, with a guy who was plugged into the wall and died when he followed the cord to the wall and unplugged himself. It sounded like it was a big deal, and something that you'd see on Adult Swim or something so we quickly formed a group and effectively looked through our leads and resources. Not too long after we found the block where the short originated from, and even the creator himself. He later released it, but it wasn't quite what OP was remembering. I guess it mostly was, but the art style was pretty normal and the whole unplugging bit was implied and not shown on screen. It was a cool search and the fact that we solved it so quickly is something worth noting, but the short itself wasn't all that special.

Also I'm gonna throw it out here just because I have to- while A Day with SpongeBob didn't even exist I still think that search was worth every minute and lived up to the hype that searching for the movie itself had.

I'd say the bits and pieces of All Lights Fucked on the Hairy Amp Drooling that surfaced have been nice as a criminally underrated find. I know we're just needing to wait on the other tracks to be released, but I'm hoping we won't have to wait too long for that. While it's still ongoing, in a similar vain to what Radiant Lloyd Firefly said, the current search for Saki Sanobashi and the band behind "the Most Mysterious Song" have been a blast - even if Saki is confirmed to be a hoax (99.95% sure it is) and we never find out who recorded the song.

As far as other pieces of media goes, I'll need to check them off my list first to see if they lived up to any potential hype, but Cards of Death (1986) and The Basement (1989) come to mind. I think Bloodstream (1985) was lost for a while as well or it was so obscure that only one or two horror review outlets acknowledged its existence before old clips surface. I've seen that one, but I found it rather 'meh' and the social commentary the director made on how the film and distribution industries are was the greatest irony I had seen in a while since it failed to get picked up.

Cracks transcends the scare factor; it's more eerie than scary, though it's totally understandable why a bunch of kids in 1976 were scared of that face.

The best part is that we're still probably not even being told the truth about it... the silence is deafening.

Rapsittie Street Kids: Believe in Santa, for all the wrong reasons.

yeah, i agree with that lol