I rarely (if ever) see discussion about outsider artists here.
Some of my favorite outsider musicians are Daniel Johnston, Wesley Willis, and Wild Man Fischer.
I've been working my way through Jandek's prolific discography recently, as I had been putting it off for far too long. He's a little different than most of my other favorite outsider artists because he doesn't appear to be mentally ill, just a bit mysterious and nontraditional. So far, I think Nancy sing is his best song.