GuyPerfect: You also have three custom levels outside your playlist you linked. Also, I remember that your YouTube name was PerfectKiosk (or something like that?) some time ago.

möbius: Apparently you haven't read my
review about Tijmen Bok's levels in Lemmini Level Pack Topic (you said that you discovered his levels recently). That makes me wonder if I write that kind of stuff there in vain.

After all, you are one of the very few who I thought to follow this Lemmini topic. Also, yeah ssam1221 was familiar to me, but this guy seemingly put that download link in his channel recently, so I downloaded his pack just like a week ago! UltimateJay was familiar to me, too.
A very nice thread indeed, I know lots of YouTube Lemmings people, I'll post here those who haven't been active lately or don't have an account here if it's ok.
People who haven't been recently active:
Forum name (link to profile) - YouTube name (link to Youtube channel)
alfonz1986 -
alfonz1986Dodochacalo -
DodochacaloFernito -
Fernito69Giga -
GigaLemLemmy556 -
Lemmy556MASTER-88 -
metroidmaster88Nicolas Eymerich -
EllischantNortaneous -
NortaneousRubiX -
rubix2007Tim -
timfoxxyYawg -
JustAnotherEgoAnd some people who aren't here as far as I know (link to YouTube channel):
BizkitPark21BulletRidej (Has levelpacks in the Lemmings Level Database under name BulletRide.)
doggycharly150 (Has a levelpack in the LLD under name doggycharly.)
dutjuup (Martin Zurlinden, he hasn't got any videos but I find him so remarkable Lemmings dude so I included him to the list)
karmew32 (Also known as QBeez, has levelpacks in the LLD under this name.)
LacktardoloftyDMad4Maniac (Has levelpacks in the LLD.)
MikauSchekzen (Also known as Tijmen Bok)
noooodl (Doesn't have Lemmings videos anymore?

That's why the strikethrough)
PacGuy765PaHeLemmSonic8000ssam1221UltimateJay1989ValientlinkLet me know if you'll find mistakes in my list about who is who etc.
Then I know of course Adam's, Crane's, Gronkling's, Insane Steve's, Luis' and Pieuw's channels, but maybe they want to tell something about their channels? : )
I don't have videos in YouTube, but I have an account so I can comment others' videos.
And yeah, I listed mostly those who show custom levels in their channels. If I'll add those who have things like playthroughs of Lemmings, then the list will be even larger. They are more unknown to me than custom level makers.