<p>Both, or maybe German and something more unfamiliar than Russian. I’m not a linguistics student, but I heard that linguistics majors are advised to study at least one language that is very different from your first and second languages. Perhaps Mandarin or Japanese. I recommend German because a lot of research is done in the language and it has much to teach you about your presumably native language, English - and there’s nothing like learning about languages by familiarizing yourself with the language in which you think. And as a classics major, I would ask you to give Greek or Latin a thought too.</p>