Afrikaans: Because it's lekker.
Russian: A cool language. My cousin knows it, and it's the first language of this awesome girl I know. Plus it'll be invaluable for a history professor. This is my first choice.
Arabic: Useful, possibly good for history, and my great-aunt would be proud. She can't speak it any more, though. She and my grandpa had Lebanese parents. This is my second choice (tied with Mongolian).
Hungarian: A cool language, and could be useful if I ever go to Hungary. I think it's best to learn a country's language before visiting, and I'd like to go to Hungary.
Mongolian: I really want to visit Mongolia often and for long stretches if at all possible, since I have a fairly strong interest in its history and culture.
Georgian: I love its alphabet, look, and sound. Friggin' useless, though.
Gaelic: I don't like Gaelic, but I do like Breton. Some of my favorite music's Breton, so it might be nice to know. Definitely low-priority, though.
Oh, and I forgot Lithuanian. An awesome language, and a fair amount of interesting history books are in it and no other language.
Ewww. Latin is dead for a reason.
I just don't like Gaelic. It looks awful. Breton looks and sounds good.