I'd go for Vin Garbutt, but because he's such a funny man, the greatness of his singing could be overlooked. Some of my other favourites e.g. Nic Jones and Martin Carthy have a singing style that has been "manufactured", but - to my ears - Vin sings without any such affectations. Wonderful stuff. I,too,love Paul Brady's Irish folk voice, but I'm not happy with his affected "rock" voice.