Have a look at Deitsch, in my opinion the best current German folk act,
e.g. Die Rheinbraut, Vedder Michel, Wirtshaus-Zwiefacher, Kerwe-Lied, Heinz fährt Karussell.

(And I have heard Mike Harding having played their extendend German-Scottish incarnation 2Duos three times in the last twelve months.)