I’ve really only been following two streamers/gamers, beside the obligatory AVGN/James and Mike. Contrary to the latter though the others I follow are actually serious about their gaming and try to do as good as possible. And they are extremely good at what they do. They’re pretty particular in what they play though, so you’ll have to like the games they play. Not sure about the ‘lesser known’ qualifier, especially the first quite a few subs;
Ryukahr: American streamer who plays Mario games, especially Mario Maker. Branches out every once in a while to other things, which is equally fun. Probably one of the best Mario players out there, his ongoing main feature series, the Mario Maker Super Expert No-skip, is a lot of fun. He’ll get all kinds of levels, from good to terrible and he’ll try to use his skill to clear as many levels as possible before game-over. He is a cool guy, never gets angry and never swears, even he dies 30 times on the same thing. He has new videos and new streams regularly every week.
Silvarret: Dutch streamer that plays management/city building games. In particular he’ll play Planet Coaster, Planet Zoo, Parkitect or Cities Skylines though that last one seems to be on the back burner for now. His creativity knows no bounds and is interesting due to his creations always having a basis in reality somehow. He’ll create the most beautiful theme parks, zoos or cities you’ll ever see. He also has a very soothing voice that’s easy and pleasant to listen to. His output is a bit irregular because the channel isn’t his main source of income.