I like Alison Krause's voice. I like a lot of young sounding voices. Jean Ritchie's clear voice always sounds young to me. Maddy Prior's voice is high and strong. June Tabor has what is probably my favorite voice.

Frankly, for me it's the expressiveness, fullness and on-pitchness in a voice that make me like it. It's also phrasing, emotion and a lot of other things besides the voice that make me want to listen to a singer.