Most of my Youtube channel subscriptions are for video essays. I like all sorts of media and I like hearing interesting scholarly critiques of things. If you have more recommendations, I'd be interested!
Video games: Mark Brown, MatthewMatosis, PBS Game/Show
Film: Channel Criswell, Every Frame a Painting, KaptainKristian, Now You See It
History: ExtraCredits (their video game commentary is pretty meh)
Anime: Mother's Basement (sometimes interesting commentary, but tends to be too angry and I don't watch that much anime to click this one often)
Media in General PBS Idea Channel, PBS Off Book, Ryan Hollinger
Then there are just entertainers that I really like.
Andrew Huang - doing really interesting stuff with music!
Chuggaaconroy - really entertaining Let's Player, very mainstream
Giant Bomb - funniest guys on the internet reviewing video games but mostly derping around. <3 Vinny and Dan.
ProZD - Hilarious voice actor