I'm torn, really. Realistically, the only non-English language I've found to be useful is Spanish, which I can speak and understand to some degree. I'm not fluent by any definition, but I know enough that I could get by with a few stumbles along the way. That said, it's hardly my favorite language of the ones I've encountered. Phonetically, I'm rather fond of Italian and Japanese, so both are naturally among my top choices. Then there's another part of me that wants to learn
ASL for no other reason than I feel it would be interesting to know. That said, considering I don't know anybody who's deaf, I'd imagine I'd never actually have cause to use it, which tempers my desire to learn it a little. All the same, I find it hard to choose between those three languages.