Wild Theme has already brought me the tears on some occasions. Whistle Theme, Smooching and Wild Mountain Thyme are others that I can not fail to mention, they do not have lyrics, but, the melodies are deep and convivial with me.
Other songs that move me a lot are:
Wild West End (My first musical passion in the DS work.)
Lions (Very engaging too, the rhythm, the atmosphere, starting from the introduction to the end.)
Down to the Waterline
You and Your Friend (There is always a sensual atmosphere)
Love Over Gold
It never rains
Only end of TOL
BIA- (especially the Mandela 1988 version)
Iron Hand (especially the version of Timothy White sessions 1992 and Dublin 23.8.91)
Of the solo career, the one that moves me the most is So Far From the Clyde, the melancholy and metaphor are deep in this.
Sailling to Philadelphia
What it is (studio version or live 2001 with Bonnie, Bonnie Banks O'Loch Lomond)
If this is goodbye
I Dug Up A Diamond (melody and duento between Mark and Richard on guitar)
Dream of a drawned submariner (Another strong song)
Long highway
Are We In Trouble Now
Darling Pretty
The Scaffold's Wife
Remembrance Day
At the moment, these are the ones I remember, they are the unique sensations they bring!