Alfie Boe singing "Bring Him Home" in the 25th Anniversary Concert of Les Mis. This is Jean Valjean's prayer that the boy his daughter loves will be kept safe in the coming fight.
And I am rather fond of this song, too (although the singer has far, far less experience than Alfie Boe):
"Empty Chairs at Empty Tables." Marius, mourning the death of his friends. Video version here because embedding isn't allowed for that one. I watched my grandmother's recorded version, and I spent the whole time wondering who the kid playing Marius was... I was a more than a little bit surprised when I found out. :-P