Here's a bit of a mixed list of good channels indicative of my interests, in no particular order, and excluding traditional media orgs and stuff like bands (though as an exception I'll shout out tiny desk by NPR):

Technology connections - video essays about household tech

Techmoan - retro AV gear and adjacent stuff

Nostalgia nerd - video essays about retro games

Cathode ray dude - video essays on old video production and industrial tech, and adjacent stuff

LGR (+ Blerbs) - classic PC video games and hardware

Retro bytes - more video essays about retro games

Hbomberguy - video essays about games and politics

Philosophy tube - video essays about philosophy

Evan edinger - mix of topics (often transit, language, travel, differences between US/UK) about an American who's lived in the UK and Europe

AudioPilz - retro audio gear

Ringway Manchester - amateur radio

Jago Hazzard - trains and transit, particularly London

William Osman (+ 2nd channel) - unhinged engineer currently trying to farm

Kurzgusagt - edutainment about science, health and philosophy

Binging with babish - cooking

Bigclivedotcom - electronic/electrical engineering

Macho Nacho productions - retro game console mods

Modern vintage gamer - retro game emulation and adjacent stuff

Slow news day - topical UK news analysis

Chris Spargo - short documentaries about random oddities

Tom Scott (+ the technical difficulties) - currently visiting various interesting sites around the UK, general documentary content

Pad Chennington - video essays about obscure music genres and trends

Linus Boman - typography and design

Humano Studios - vinyl DJ sets

James Hoffman - coffee documentaries and reviews

Notjustbikes - public transit and urban planning

The Serial Port - 80s/90s era Telco and ISP tech

Clabretro - similar stuff, maybe a bit more stuff about old servers

Abroad in Japan - travel content and entertainment for Japan hosted by a British expat

Rion Ishida - walking vlogs in Japan focusing on travel

Nilered - science experiment edutainment

Defunctland - abandoned theme park video essays

Adam Ragusea - cooking and health

Lockpicking Lawyer - guy picks into every lock in front of him

Gary's Economics - video essays about why everything is going to shit (economics)

Adrian's digital basement - retro tech repair

How to drink - cocktails and their history

VWestlife - more retro tech repair

Adam Martyn - British broadcast media history

J.J. McCollough - pop culture video essays

Summoning Salt - speed running video essays

Wendover Productions (+ half as interesting and jet lag the game) - video essays about logistics and adjacent topics. HAI is more short content and general topics

MattKC - retro game reverse engineering

Self sufficient me - gardening

Ogmios - pov vlog with a fun voiceover

Level1Techs - more tech content

Ambiguous amphibian - game challenges