I have now restrained to said selection. These are some of all of Libera's moving songs which do so in a specific way, so I hope that's what you expected.
It's interesting, as sometimes it's the music, sometimes the lyrics, sometimes a single voice, sometimes a mix. And sometimes it's the live experience which makes a difference and can open a song for me. So to each song in alphabetical order:
1. Songs that touch me so intensely that they require inner stability as a prerequisite for a listen (otherwise I must skip them)
Ave Maria (Robert Prizeman)
The pleading is so palpable already in the melody. I love every version I heard from Libera, on albums and live.
Ave Maria (Vavilov/Caccini)
Solo sung by Tom Cully. I know some fans prefer the Steven Geraghty's rendition, and yes, he is wonderful. Marvelous voice and he sings this difficult piece flawlessly, admirable! I love to listen to him for this beauty and I love to listen to Gabe for the goosebumps he causes me with his deep notes at the part from
2:52. But for the heart, I always return to Tom, who sets a sensitivity into the song with his haunting voice and by the phrasing that is unique and irresistibly draws me in. This lasts all the way through. Since I heard Tom's recording, no other version of the uncountable interpretations of this piece has evoked a similar mesmerised, so moved feeling in myself.
Do Not Stand
Solo sung by Ben Crawley. Robert's setting of the words is unrivaled, I can't imagine anything more adequate. Such infinite tenderness, perfectly matched by Ben's feathery voice and the gentle, meaningful lyrics.
If
Well, only recently I wrote about why I find it so touching, so I simply
place a link here. Super-serious song. And I agree with you, Tully, that, even though I do, one doesn't necessarily have to refer to Anne Frank and her time to be moved by this piece. It's timeless and I think that many people wholeheartedly agree to the words.
Sancte
Again such longing in the music, gentle introversion, then streaming power - yes, that song touches me deeply.
Stabat Mater
Very, very, very stirring! Composed love in despair, pain, the sighs, the perfect setting of the Stabat words and then Isaac voice full of feeling and even expressing the weeping with his voice (wow!), then the choir taking over, increasing the dramatic feeling. The tune is magic and all rounded. This song is tender and overwhelming at the same time. The most touching Libera song for me and definitely no song I can always endure due to its poignancy.
2. Particularly personal songs
Secret
I had described my feelings in this forum before, so I hope it's okay to just partly repeat myself, as nothing has changed:
Secret for me is like looking into a mirror, not for the lyrics which I don't mind, but for the music in every single sense. I get a special, very pleasant childhood scene during sunset, a blackbird singing on our neighbours' house, my family and the others around us are at home and enjoy their evening. It's a 100 % feeling of peace and calm joy. And no wonder it represents summer. So,
Secret is the most precious Libera song for me. The music in each respect feels as if Robert had set myself to music. I've never had something similar before. Very important song for me and most dear and precious to my heart and soul.
Vespera
also evokes some early memories I can't concretely grasp. It's the sound of the keyboard which immediately has me transferred to back then, and it feels sheltered, safe and there is a diffuse atmosphere of excitement, music, concert. This basic feeling is maintained over the entire song, the tune, the special harmonies, all contributes to it. Like
Secret,
Vespera spreads a purely pleasant feelings to me. I have no idea why exactly it creates such a result. But I react the same way to the typical Pat Metheny sound. Strange, as I was not at all familiar with such music either way at that time.
Wexford Carol
An inseparable unity of contentment and peace and as such balm for the soul, gently swaying, meditative. Only with Libera. Their version is the ultimate. I prefer Isaac's version from Armagh, again for personal reasons: I watched the Armagh DVD for the first time around my first Libera concert in the UK 2016 and everything turned out so well! The travels, London, meeting with others, a superb concert; there was an overall joyful atmosphere persisting over those days. And this always resonates, when I listen to the Armagh
Wexford Carol.
3. Other songs which touch me in a special way
In the bleak midwinter
Reading the title is enough to capture me by just hearing Libera sing it in concert via my inner ear. Every choir seems to have its rendition of the song, but the one by Libera gives the song a special meaning and they sing it just so gently.
Mother of God
Very touching for how modest and intimate Libera's rendition is.
Something Sings
A very contemplative song from which I took my forum signature words that are so comforting and so suitable and so true: "But in the dark and cold of things / There always, always something sings." A great combination of mysterious sound and peace, which never fails to find the ground of my soul.
Three Ravens
Another kind of moving effect!
That song is so dramatic and of such a harsh beauty (hope that hits it correctly), I just can't resist. It just catches me and doesn't let me go. In the second interlude, before the ending part, it's as if the voices are dancing around me and the turbulence in this part and the brilliant singing fascinate me! I always turn the song very loud so that it feels like being surrounded, locked in by this thrilling music. Not sure what people thought of me recently when I was listening to
Three Ravens in the car and at a red traffic-light forgot to close the window.
Wayfaring Stranger
My first encounter with this song was a guitar/flute version, and I always assigned it to such a very much reduced form mirroring the lonely person. But the Libera arrangement by Sam Coates unites so many emotional states - like loneliness, longing, insecurity, resolution, hope etc. - and develops that in such a powerful way that I go from goosebumps to goosebumps, especially when sung live. The song has got another dimension for me through Libera and this unconsciously gets to me each time.
We are the Lost
Apart from being very beautiful, it has that historic background, so I agree with you here.
). For my part, several songs already touch me by their melody and singing. Do you have in mind certain songs touching you in a more "complex" way, for example by the story they tell, a certain situation you connect a song to (apart from concerts, which would make the list too long again for sure 
