My favourites were Werner Laemmerhirt, Lydia Ouvray, Herman van Veen (though he's Dutch), Liederjan, (some) Ougenweide, among others. A guitarist I liked was Chris Jones (lived in Germany a long time), but died just over a year ago. He used to play with Kieran Halpin, who gave me the bad news at a Dublin gig last year.

There's a number of young (and not-so-young) folkies around Hannover/Hamburg playing Irish and acoustic folk as well as their own compositions in bands such as DeReelium (Barbara Steinort), Cara, Ceolta (with a good piper, Achim Gretsch), Déirin Dé, etc. I used to know a lot more, eg, Ten Feet Below, but I don't know whether they are still playing. A good long-running Irish group in Stuttgart is Bachelor's Walk.

Friends of mine in Hannover sing accapella (all women) in Herzen in Terzen--very funny and well worth seeing if they come your way (their website is here ).