I've had a bit of luck finding youtubers/twitch streamers who are content to let some dead air go by if they don't have anything important to say, and definitely don't do any yelling or screaming. It's a real nice change.
Partially I'm just making this post to share the few I've been watching the most:
Jagged Appliance, a Supreme Commander player and caster.
Growling Sidewinder, a DCS pilot who goes into detail about dogfighting and BVR fighter jet tactics.
Tasteless, a Starcraft caster who plays Brood War and chess in the Korean timezone.
Been really into AquaFPS lately, he's pretty easygoing, gets kinda shouty when upset, naturally but his usual demeanor is low-key. I don't watch his twitch streams maybe he's worse there but his Youtube is top notch gamer slime. Unfortunately he associates with General Sam a lot who is a lot less wholesome, I would even say he sucks but he is pretty funny in that crude asshole kinda way.
Besides that I'll always shill for Castle Super Beast podcast and the pair who host it, Woolie's channel WoolieVs on youtube and twitch is great so long as you like fighting games and PatStaresAt is basically my inner spirit goblin