Alan Tutorial
I LOVE Atomic Shrimp's videos...
No way, I was watching an atomic shrimp video while reading through the forum :D Also I used to watch Cybershell a ton
I am going to absolutely love AlanTutorial, I adore that kind of Youtube ARG stuff!!! The description kinda reminds me of the Happy Meat Farm ARG which is also fantastic and you should go watch.
As for obscure channels that I like, it's kinda hard for me to tell what would fall under obscure but:
Peter Knetter - Sonic-ishh youtuber, they used to do a bunch of skits and also fun YTPs
Blue Horizons Inc - Not /exactly/ an ARG series, but all of their videos are like fake company tapes that are VERY unsettling and it is a fantastic watch. Blood warning on the "handshakes" video.
Characters Welcome - Some kind of archive of a stand up comedy set, where like people act out a set without props? There are some good ones there.
Internet Comment Etiquette with Erik - Skits about how not to be a good person online
Bryan Lunduke - Really interesting computer discussion videos
KamSandwhich - Scott the Woz but for board games
friendlyjordies - /probably/ not that obscure anymore since penguinz0 covered them before, but they like cover evil companies in Australia and hes really funny
Gamechamp3000 - Videogame Challenge videos
Stryder7X/TheZZAZZGlitch/pannenkoek2012 - Hyper analytical videos about very specific coding issues in games (paper mario 64, gen 1/2 pokemon, and mario 64 respectively). pannenkoek might be less obscure because he spawned multiple memes tho
edit: snipped some of the quotes