I'm going to learn Latin, and after that maybe Italian. Thus far the only language I know other than English is German, but it's tainted because I would deliberately mispronounce certain words and speak in broken grammar to mess with my teacher. Joke's on me I guess.
I'd also like to learn Greek. I'm very interested in one day reading the Bible in the original languages it was written in, which means I'll eventually have to learn Hebrew and Aramaic as well. Big goals.