I've often thought I'd like to hear a folk cover album of X Ray Spex's Germ Free Adolescents. It's a very modal album - would sound great on accordions, fiddles and DADGAD guitars. I can imagine Martin Carthy, John Kirkpatrick and others singing those songs very well.

An entire album of the sort of folk songs Sue Ferrar experimented with on her "A Boy Leaves Home" album would be great (there's only two on there...)

A second album from James Raynard

A second album from Michael Rossiter

A Rick Rubin-produced Tom Paley album

Oh, and here's a cheeky 6th: a Voice Of the People-style compilation of the best singers I've heard doing floorspots at Sharps Folk Club, Musical Traditions and Cellar Upstairs. Sharps in particular. I've only been there twice, but both times I've been struck by the idea that a decent, straightforward recording on two good mics, would make for a great Alan Lomax-style field recording of an album.