Anything you can get from our own Aidan Crossey aka derrymacash. Excellent!

I also recommend Altan, esp. their first two tapes.

I could listen to the Chieftains forever and not get tired of it!

Also on the Mudcat, a great group from OZ or New Zealand, so not strictly Irish...listed their CD on here, where I found out about it and ordered it. It has been one of my favs for a long time now. Group is Lothlorien; CD is Greenwood Side.