if you want old time recommendations, I don't listen to much, but these are a few I come back to and play on loop from time to time:
Dr. Humphrey Bate and his Possum Hunters - "How Many Biscuits Can You Eat", "Ham Beats All Meat"
The Crook Brothers String Band - "my wife died friday night"
Deford Bailey - John Henry
Blind Willie Johnson - Dark was the Night, Cold was the Ground (this song got sent up on the Voyager Shuttle, which is supposed to land on another planet and immediately start pumping humanity's greatest musical accomplishments for the aliens...Ry Cooder called it "the most transcendent song ever recorded on American soil, which is kind of cool)
Son House - Death Letter Blues (Oh my God, if you watch a live video of this song...that was the first time I got why people liked the blues so much back in the day. Son House said the blues were when someone murders your wife or something, and you don't know whether to beat him to death or sit down and cry, and you end up choosing crying)
Mississippi John Hurt - anything rules, but I really like Nobody's Dirty Business and a few others I can't remember
There's so, so much more amazing music that I don't feel qualified talking about it, but this is stuff I like.