O Holy Night
O Come All Ye Faithful
O Come O Come Emmanuel
Godhead Here in Hiding (first heard it sung at a Catholic service a few months ago)
My Jesus I Love Thee (the melody, mostly)
When I Survey the Wondrous Cross
Christ Rising Again (Tallis - any of his Protestant anthems)
anything written by Charles Wesley that I've seen
like a buffet of historical / pre-1900s Western hymns of any tradition, hmm. If music be a guide to the proper Church (and I am not a musician or any sort of student), then am utterly confused but probably couldn't go Orthodox. Liturgical refinement is very nice, but sometimes the American 19th century, Evangelical revival hymns are their own sublime comfort (not always in the happy, carefree way.)