And I thought it'd be easy!!!
Can't promise strictly acoustic, but here goes :

Kate Wolf - Give Yourself To Love(Live double)
Archie Fisher - archie fisher
Davy Graham - Folk, Blues, and Beyond
Alan Stivell - Reflections
Marian Henderson - Cameo (from Oz)

But what about :
The Watersons - Frost and Fire
La Bamboche - la bamboche
Gary Shearston - The Springtime It Brings On The Shearing (from Oz)
The Pennywhistlers - Folksongs of Eastern Europe
Judy Collins - The Judy Collins Concert

And not forgetting :
Muckram Wakes - A Map of Derbyshire
The Fate o' Charlie - Archie Fisher, Barbara Dickson, John MacKinnon
Dick Gaughan - No More Forever
Kris Kristofferson & Rita Coolidge - Full Moon
Rory Block - Rhinestones and Steel Strings

But hang on, how could I possibly live without the voices of Roy Bailey / Stan Rogers / Bob Fox / John Gorka / Rod Paterson / Gordon Bok / Rene Geyer / Maria Muldaur / Frankie Armstrong / Cathy Fink & Marcy Marxer / June Tabor / Emmy Lou Harris ??? - or that wonderful 1920s-30s Gospel stuff???
Oh this is WAY too hard; I'm not goin' sailing!!!
Cheers from Down Under, Rich-Joy