For me it's DJ Peach Cobbler. I've been watching his videos since he had around 2,000 subscribers. Now it's nearly 450,000.
He used to mostly make videos on games, now he does a lot of history stuff too. He also has a little satirical news show, and a few tasteful shitposts. A really diverse YouTube channel.
What's your favorite YouTube channel that's not a mainstream big-name like pewdiepie, mrbeast, ksi, etc...?
https://youtube.com/@FishingHistoricPlaces - Brief visits to places, mostly in New England, with interesting historic and natural history info. Rarely any fishing.
https://youtube.com/@EarlyMusicinadifferentway - talented multi-instrumentalist and composer playing early music and his own compositions and improvisations in an early music style. Interesting videos too.