I doubt he's considered lesser known, but Scott the Woz is under a million subs and very funny. His videos range the gamut from reviews on specific games, topic videos on things like software available at each consoles launch, game rarity and preserving old games, the companies that make games and some of their history, and 'reviewing' shovelware. It's a Nintendo-centric channel, but not Nintendo exclusive.
Larry Bundy Jr. aka Guru Larry is a man who's lived through nearly every console generation and has a wealth of old and interesting facts to share in his 'Fact Hunt' series. The titles all sound like pure clickbait, but he has an engaging voice and a charisma that shines as he talks about odd and largely forgotten topics.
Spawnwave runs a channel where he does a short summation of the most recent gaming news every weekday morning. Nothing particularly fancy or amusing but it's a nice way to start the day and he often informs of things I had no idea about. His breakdown videos on various pieces of tech and how to mod existing consoles are entertaining as well. I'd recommend starting with the Ring-con breakdown as it's got an interesting bit in it that makes the whole thing work.