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 - alfonz1986
Dodochacalo - Dodochacalo
Fernito - Fernito69
Giga - GigaLem
Lemmy556 - Lemmy556
MASTER-88 - metroidmaster88
Nicolas Eymerich - Ellischant
Nortaneous - Nortaneous
RubiX - rubix2007
Tim - timfoxxy
Yawg - JustAnotherEgo

And some people who aren't here as far as I know (link to YouTube channel):

BizkitPark21
BulletRidej (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.)
Lacktardo
loftyD
Mad4Maniac (Has levelpacks in the LLD.)
MikauSchekzen (Also known as Tijmen Bok)
noooodl (Doesn't have Lemmings videos anymore? That's why the strikethrough)
PacGuy765
PaHeLemm
Sonic8000
ssam1221
UltimateJay1989
Valientlink

Let 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.

just letting everyone know that I'm BizkitPark21 from YouTube. 

hey, I couldn't find the "Introduce yourself" section or if there even is one.

I've been a fan of Lemmings since I was little.  the proof?  I actually own copies of Lemmings on the NES, SNES, Genesis, Game Gear (which is pretty much like the Master System), Gameboy, PSP, Playstation, and DOS (don't know which version).
I also own other Lemmings games like Lemmings 2: The Tribes for SNES and Genesis, 3D Lemmings (or Lemmings 3D, whatever way it is) on Windows (PC) and Playstation, Lemmings Revolution on Windows (PC), and Lemmings Paintball which actually also contains the Windows version of Lemmings (plus ON!ML).

anyways, to keep on this topic, my favorite music version would be the Sega Genesis