The smallest channel I’m subscribed to is Flexperiments, a channel focused on modifying fountain pens to make a super flexible nib and have insane line width variation that I have never seen before. If you like fountain pens, you might find it interesting.

CGP Grey kicked me off on this intense obsession with getting rid of First Past The Post voting, but he has many other very well made videos. Cannot recommend him enough.

Notable runners up:

Steve1989MRE

JoergeSprave (the slingshot channel)

Fresh from the Farm Fungi - he is a mushroom farmer from Colorado. He has a ton of valuable information on growing mushrooms and running a business. He also has a few series of videos on very interesting experiments such as growing boletus, morelles, and cordyceps.

Microbehunter - he is a biology teacher that runs a microscope channel. His videos are very useful for learning the basics of microscopy.

Huygen Optics - I’m not sure about this guy’s background. He worked in R&D for Phillips in the 90s and he knows a lot about optics and chemistry, but I don’t know much more. He has built some equipment in has garage for sputtering metals on surfaces and has some pretty cool videos.

MissOrchidGirl - she is more popular than the others. She has great info about caring for orchids and a fantastic orchid collection.

Ben Felix - he is a portfolio manager with very solid financial advice. He supports his claims with research articles.

https://www.youtube.com/watch?v=xLfFWXUNJ_I It’s more of one playlist than a channel about quantum mechanics on Russian, but as I see it has English subtitles. A fairly clear explanation with a small amount of simple mathematics, probably the minimum that is possible. It helps to understand at least a little such a complex and illogical science for the average layman.

Combo Class is a neat math education channel where things are often on fire or falling apart in the background in a way that’s fascinating on top of the math itself

Side note, I have no idea how many subscribers counts as obscure. It seems relative to the size of the niche. Or maybe I have no idea how big people are relative to how much I care about them. Like I would expect Ben Levin (music theory and production creator) to be closer in subs to Adam Neely (same) but he’s an entire order of magnitude lower. Like is CJ The X (video essayist) obscure enough at 341K subs?

Inside China Business

Its a chauvinist doing 10min reports on China’s business practices. Its mostly a guy presenting well researched information about how China is eating the us’ lunch and being frustrated about it.

My husband recently found this gem of a cooking channel that we both love. Chef Jean Pierre He’s hilarious and the food looks amazing.

Matt Brown - security researcher and bug bounty hunter

Robert Murray Smith - general mechanical engineering tinkering, lots to learn

TheCod3r - console and other electronic repairs

Wesley Kagan - builds cars but is just an overall genius and entertaining

Joe Grand - hacker, genius

There are more popular/sometimes better people and channels in each genre but I’ve stuck to those with under 1 million sub’s. I’ll assume people like Colin Furze, Ben Eater, Computerphile are already too well known for this thread

twoodfrd - the guy repairs guitars with his soothing voice and lots of technicial knowledge

Bobby Fingers. He makes diaramas of weird things and then buries them in the woods for people to find. Doesn’t make videos too often but they’re hilarious.

Kyle the Scott. A Scottish cisman with a kinda effeminate voice who once did a dramatic shirt rip to prove he is in fact cis, in the middle of a half hour essay about why it shouldn’t even matter and “transvestigations” are bullshit.

But his normal schtick is media criticism, covering franchises like Star Wars, Halo, and Assassin’s Creed. They’re just genuinely good reviews that aren’t afraid to get into the politics where appropriate (including explicitly rejecting some of the more popular bigoted takes) but honestly feel it’s about the way that particular lens affects the media, rather than being an end into itself.

Aussie Wood Shed

A really tiny channel I like is Don’t Look East. Currently less than 3000 subscribers and most videos just get a few hundred views. He does unscripted travel vlogs about rarely visited destinations, mostly in Asia and Eastern Europe. For example he recently travelled the entire Thailand/Myanmar border by motorcycle.