Professor dave explains: science education + science deniers debunk videos.

Chubbyemo: medical cases breakdown primarily focusing on biology.

Technology connections: deep dive into everyday electrical appliances, not exactly science but well researched and sometimes he goes into a sciency part.

Electroboom: electrical engineering with some humor.

Steve mould: scientific deep dive into random questions and phenomenons.

Codyslab: mostly homebrew chemistry but also otger things.

Tierzoo: fun animal world education.

Applied science: science projects and deep explanations.

The thought emporium: mostly biology but also other stuff, some really crazy biology projects (running doom on rat neurons...)

3blue1brown is phenomenal. It taught me how to understand a bunch of things better than studying them academically did.

“Journey to the Microcosmos” is wonderful.

ZeFrank has quite a lot of accurate biology if you want a humor channel in there.

PBS Eons is great.

I haven’t checked them out, but I feel like things like Nebula or CuriosityStream may be becoming better sources for this stuff than YouTube is. YouTube seems like it is becoming a chess, and I see no real reversal of that in the cards any time soon.

Anton Petrov ("Hello, Wonderful Person!") is quite good IMO.

PBS Space Time and Eons (and as others have already said, Journey to the Microcosmos).

Kurzgesagt is fun and AFAIK always tries to be accurate (they've been quick to publish correction videos when necessary).

I'll second other's recommendation for CuriosityStream and Standup Maths. Matt's also part of at least one good podcast, "A Podcast of Unnecessary Detail" which is informative and entertaining.

Clint's Reptiles: He does great videos covering phylogeny as well as pet scores for individual species.

Professor Dave Explains: A huge variety of content explaining science, my favorites so far are on phylogeny.

Mothlight Media: Videos on evolution of modern and extinct species. One of my favorites!!

Others mentioned PBS Eons, you would most definitely like it.

Hyperspace Pirate is making something in his garage. I don't really know what, but involved cryogenics and electric arc furnaces.

Tech Ingredients seems to be gearing up to arm the resistance after the seven hours war.

Atomic Frontier is a young Aussie kid trying really hard and doing a great job of teaching pop science.

Seeing all this science and nature content made me think of watching CBC's The Nature Of Things as a kid. Their long-time host David Suzuki managed to piss off some powerful people, including the Prime Minister of Canada, so make of that what you will. It seems The Nature Of Things is still going, and they have a YouTube channel.

Angela Collier has some great stuff on physics, and she's a great teacher.

From the ones ive seen mentioned, I second Electroboom, Crime Pays But Botany Doesn't, Practical Engineering, ZeFrank, and Kurzgesagt.

If you like biology and evolution, I would recommend Lindsay Nikole.

If you like deep dives into various types of engineering, I would recommend Real Engineering. He does a lot of aviation and aerospace stuff.

Skeptics Guide to the Universe. They're mostly a podcast but have good content on YouTube as well.

Flammable Maths and matholiger for maths.

Cody's lab for general crazyness. Currently building a mars base replica.

Al muqaddimah for arab history and kobean history for european history. Dime store adventures for new england history.

Bruce Yeany for small and fun science experiments.

Computerphile. Periodic Videos.

Deep look for (insect) biology.

EEVblog and greatscott for electronics.

Engineerguy for deep dives into products.

NightHawkInLight, NurdRage, for fun diy chemistry.

Sui Generis Brewing for fermenting.

Dr. George S Diaz PhD nuclear physicist goes through the math and the experiments. Has a very satisfying voice and you never see him so no egotistical BS

Mark Rober is always a good one. And Vsauce if you prefer OG YouTube quality.

Sixty Symbols is great.

Damn Everyone here is nerd too. I am not alone.

Lot of stuff already listed so here are some more niche channels if you are interested:

Meteorology: WeatherWest

Geography & climate: Casual Earth

Nutrition: No Lab Coat Required

Journey to the microcosmose is pretty great.

This woman give fun talks about paleontology.

https://www.youtube.com/@LindsayNikole

ThreeBlueOneBrown is a good math channel, helped me understand calculus way easier than school did.

The Engineering Mindset is a good engineering one, explains how all sorts of things work from inverters to refrigeration to vehicle transmissions

Universe today. Fraser Cain. Great in depth interviews with astronomers and other space scientists.

::: spoiler list Geology hub (inactive/amateur/recent vulcanologist)

Shawn Willsey (professor of geology)

Sabine Hossenfelder (inactive physicist)

Two Minute Papers (active AI light researcher)

Real Science (dunno, but cites proper sources)

Fraser Cain (Masters, astronomy news and media)

Arvin Ash (Mechanical Engineering/ claims life long learner and posts physics content with sources)

7 Days of Science (few kids presently in Uni with VERY bright futures in paleontology reporting on papers and discoveries)

Ben G Thomas (principal Uni kid of 7DoS and apparent future paleontologist)

DJ Ware (Masters/Doc? In CS? and a former Bell Labs guy)

Curious Marc (Masters/Doc? EE? another former Bell Labs guy)

The Signal Path (Masters/Doc? EE, Grand Master of the dark arts of high frequency and radio, currently at Bell Labs)

Scott Manley (Masters/Doc? inactive astronomer, rocket nerd)

Dr. Becky (Professor of astronomy)

Stewart Hicks (Professor of Architecture)

Anything from Hank Green (SciShow) or from Brady Haron (Computerphile, Deep Sky Videos, Periodic Videos, Objectivity)

The Thought Emporium (Masters/Doc? in organic chemistry)

Breaking Taps (Professor of applied science)

Mathias Wandel (EE and former lead engineer from Blackberry)

Stuff Made Here (lead engineer from Form Labs)

Economics Explained (Professor of Economics)

Cool Worlds (Professor of Astronomy, a leading researcher for exo-moons)

Dr. Ben Miles (Physicist, head of a venture capital firm)

Stephen Milo (Masters/Doc? in archeology)

Practical Engineering (Civil Engineer)

Andreas Spies (retired EE and best source for hobby electronics and Arduino type stuff)

EEVBlog (EE)

Ben Eater (Professor of CS)

Hexibase (audio engineer)

Huygens Optics (Retired Professor? Hints like he worked at ASML. The principal optics YouTuber)

Nile Red (Chemist)

Prompt Engineering (CS, applied AI, active dev)

Robert Miles (Doctorate, AI alignment researcher)

Tech Ingredients (Applied Science)

Yannic Kilcher (Doctorate, AI researcher for Meta and probably the most advanced present researcher posting content directly)

Applied Science (Doc of Applied Science, magnetics specialist)

Others I watch were already mentioned like Anton Petrov, Nick Zentner, etc.

Smarter Every Day, Veritasium