Well, I should be able to learn Spanish fairly easily if I try, since I've already been in two and a half years of the language, so while I don't know it, I think it would be a waste of the gift.

I think it would be cool to learn dead languages, but I don't see that being of much use unless I could revive the languages through learning them.

As a result... I'd probably say the Choctaw language (rare, but not dead yet), French, German, Japanese and Welsh.

The first, the third, and the last because my family, as far as we're aware, descended from those areas. French because my grandpa learned some when he was stationed in France for the Air Force, and Japanese because I started getting interested in the language when I took karate back in elementary school.