Favorite Jewish song? Don’t know too many, really, but I do like klezmer when I hear it. If you mean liturgical verse, the one that always brings me to tears is the Mourner’s Kaddish but to call it a favorite sounds… I don’t know… just wrong, like a trivialization. I do wish I could learn to say it well, the meter confounds me every time.
There are too many beautiful Jewish prayers to possibly list. I love “Baruch ata, Adonai Elohenu, melech ha’olam, shenatan lanu hizdamnut l’takein et ha olam.” A rough translation might be “Blessed are you, Lord God, ruler of the universe, for giving us the opportunity to help mend the world.” This is one of the ones that helped open my eyes to the rightness of the Catholic teachings about penance.
As for Christian music, I’m pretty old fashioned. If it was written much past the 1700’s it might be too modern. I LOVE Gregorian Chant and early polyphony.