The really good ones you actually don’t want, because it will keep you awake.

SEA is my go to. It’s all astronomy documentaries and are amazing while also being a snooze fest. He has an entire video of just videos to sleep too!

Here are some I enjoy. All have a good voice, not overly expressively and no sudden change in background tracks. No sudden screaming/explosions/anything that will wake you.

John Michael Godier Science/Speculative Scifi, Low Soothing voice, even has a sleep playlist.

Issac Arthur Sci-Fi, Calm voice, Good background track, Long Videos

Darth Gandalf Fantasy, Soothing Voice

Forgotten Weapons Firearms, Historical and Mechanical overviews and indepth discussions. I recommend you skip the shooting range stuff if you’re trying to sleep.

Cool Worlds Science & Astronomy. Great Narrative Voice, Calm background tracks.

North02 Science, Anthropology & Natural history. Soothing Voice, nice selection of long videos.

Natural World Facts Deep Sea biology, excellent soothing narrations, very good soothing background tracks.

Posy

Not many videos but good

EmpLemon is always great, Alt Shift X has some fun ones on sci fi too, but Id guess u know both already, still might as well mention them on the low chance u dont