Considering I don't have all the time in the world to write about every single band I'd like to, here's a few channels of people who know more than me that I think everyone who enjoys music should check out.
FrankJavCee
This channel has the best music tutorials on youtube. I'm serious.
The Needle Drop
This guy isn't perfect, there are many details he leaves out and he likes punk, but he's passionate about music in general.
Spectre Sound Studios
An audio engineer who says it how it is and doesn't care if amateur bassists are offended. He should offend everyone in the band though, he does everyone a favor and tells you to GO PRACTICE!
Mac Lethal
I am far from a hip hop fan, but Mac Lethal writes some great rhymes. None of the weed or booty shaking we're used to, this guy is all about positivity, creativity and facing life. Oh and he raps really fast.
Pat David Music
The best youtube music teacher I've found so far. He has theory lessons, ear training and of course all the basic. I learned how to read sheet music with his videos and a lot of the theory is really well explained. It's on the list because everyone and their mother can play guitar, so why not play well and know what you're doing?