I'll just list here as they come to mind:
The Byrds
Poco
Chicago
Eagles
Dan Fogelberg
Harry Chapin
Emmylou Harris
Jack Williams
Anuna
Altan
Riverdance (18 times, mind you)
Lightfoot
John Denver
Neil Diamond
Kim Richey
Irish Rovers
Bill Staines
and probably a few others that I've forgotten but loved at the time.
Cheers.