Do you know the 1930 version of Erlkönig in French with Georges Thill, who makes a drama of it by bringing in a baritone to sing the Erl-king (or rather le Roi des aulnes) and a boy soprano to sing the boy? It sounds bizarre, and is possibly no longer Schubert (more like Berlioz or even Gounod in some ways), but it generates a tremendous tension, in my opinion. A curiosity. It's on YouTube, I see.
An die musik.
Perhaps the outcome of this survey, showing, say, the 10 most popular songs, could be published in the form of a Lieder Board.
Perhaps this is slightly outside the brief, but what about the Shepherd on the Rock? I have amongst others a lovely old record by Isobel Baillie. The trouble is that the insinuating clarinet melody stays in the mind for days once you've heard it!