I could list a bunch of general YTers that cover retro games among other gaming topics, but for those who mainly cover retro games I like Big Ole Words, Hungry Goriya, and Video Works.
Modern Vintage Gamer and GameHunt are both God tier channels made by old developers. MVG is ran by someone who was huge into console modding and emulation for a while. GameHut is ran by the owner of Travelers Tales, better known for Sonic 3d Blast, Sonic R, and the Lego Star Wars series. Both great channels
He mentioned on Twitter that he was disappointed by the engagement metrics on the DJ Bongos episode and wanted to take some time off. Bummer cause I really liked that episode.
Retro Game Mechanics Explained is one of my favorite YouTube channels of all time. There's an absolute treasure trove of interesting technical deep-dives about the inner workings of retro games, famous glitches, and how the hardware works. And it's all presented with clear, silky smooth animations that make everything so much easier to understand.
I'm not even into retro games that much, yet the content is so good that it has me completely hooked anyway. I'd highly recommended it for anyone who wants to learn more about computer science or the clever techniques programmers used to get things to run on old hardware.
Matt McMuscles has been on a roll lately with his retro retrospectives. The near 11 hour Double Dragon marathon was a chef's kiss. (https://youtu.be/TEn1ALxpFAg)
Becoming kind of a fan of Korone as well lately, even if I can't understand her most of the time. Really enjoying her Legend of Zelda playthrough right now. She's just having fun discovering and not bothering with doing it "right" (https://www.youtube.com/live/NWzBjSwAcvk)
I just started watching Now in the 90s. It has an episode every Friday and goes over the console releases of that week from 30 years ago. They pick a couple games to do more in-depth on reviews then shows the current value of the games with and without a box. They're 8-15 minutes.
My Life in Gaming is probably my favourite, I love the depth they go into in their full videos, and their Sunday streams are always super chill for me to just kick back and relax to retro game stuff.
If he hasn't already been mentioned, Modern Vintage Gamer (MVG) on the tubes is awesome. He sometimes adds developer insight into his videos and digs beneath the surface of the tech he's talking about.
Game Sack is a long-running channel that's one of the best retro game channels IMO. They release a video every week or two. MetalJesusRocks and his endless quest for Hidden Gems is also very good.
DF Retro has never disappointed. If I remember correctly, they literally yeeted someone off Game Sack to help do the retro content. Could be wrong about that though.