Amongst those I've asked (1 spouse, 2 friends who don't mind a phone call at this hour of the morning)

For recognizable words: Danny Boy unanimous. For tune: 2 DB, 1 for the Irish Washerwoman, but with campfire words (Oh, O'Really is dead and O'Reilly don't know it, O'Reilly is dead and...hey, I didn't write them! And kids love it.)