My answer is Gaelic (both the Irish & Scottish varieties). I am a bit biased because my heritage is almost entirely Irish and Scottish, but perhaps I feel connected to these languages even if I can't speak them--I wish I knew more about my heritage and ancestors, but I know they did speak Gaelic. To me they are beautifully sublime and subtle. And they are both in danger of dying out and I hope that never happens. Here is an example of a song sung in Scottish Gaelic called "Siud Thu 'Ille Ruaidh Ghallain":
