Morning Has Broken has to be at the top of my list. Played on flute at our wedding.
The Holy City. Was my dad's favorite, and I can still hear him singing it in a deep baritone.
Amazing Grace--not exactly a favorite, as it guts me every time I hear it, esp on pipes. Played at too many memorials and funerals, but it needs to be on the list.
How about:
Will the Circle Be Unbroken because it is just so much fun to sing?
Joshua Fit (sic) the Battle of Jericho--same reason