having just run across a pre-Rodgers recording of Riley Puckett, I'm enchanted by him for the moment.
Mary Schneider fascinates me for her apparent doublejointed throat.

I'm with Art on Bill Staines for listenability. He and Ranger Doug are two I can think of offhand that don't wear me out quickly.
For listenability, Jimmie Rodgers is low on my list..but I sure do like him--in very small doses.

Patsy Montana impresses me for her early success and ability to still yodel well after so many years.