Pretty much every BTS thingy Double Fine has ever put out. I would especially recommend their 'Double Fine Adventure" documentary ( the one about the making of broken age. SUPER educational Double Fine Adventure Documentary
These are all great! That “The Last Of Us” one was particularly good.
I have to recommend Gaming In Color, a look into the LGBTQ gaming community. You get an insightful viewpoint into where the industry is going that I don’t think you can get anywhere else! Several queer developers and gamers are interviewed, so it’s not entirely dev-focused but that’s definitely in there.
Oh oh, and Branching Paths is a doc about the indie scene in Japan–a very unique doc produced by the same person who does the tocotoco TV YouTube channel responsible for that Yoko Taro profile video that really blew up.