Carthy's version of "The Great Valerio" on the album "Beat The Retreat"
(Richard Thompson tribute!) with Maddy Prior on vocal is hard to beat-
he plays that wonderfully eerie guitar piece at the end of it which is just chilling! I'm also partial to "Skewbald", and the very odd and upbeat version of "John Barleycorn" he recorded with Steeleye Span!