So many wonderful ones mentions, but a few perhaps forgot...

The lonesome boatman (Furey's version) Blackbird Bonnie Charlie MacPhersons Lament and Lady of Schalott (spelling?) as put to music by Loreena McKennit

And notice that some refer to it as "Londonderry Aire" and others "Derry Aire"? Guess it was what side your elders were on in the troubles, perhaps.