pmgoosed...I work in financial services in Boston and have worked in global firms. Based on how our business has been growing, hands down the language to have in the coming decade will be Chinese. Now the problem with that is the number of dialects to choose from.

My former firm paid for private, one on one Berlitz lessons for everyone, it believed that strongly in the value of learning another language. I took one set of 20 hours to brush up on my Spanish and took two sets to get ready to go to Italy (on vacations, not work). I cannot speak highly enough of the Berlitz method, which teaches you just as you learned your native language. The drawback is I cannot write or read Italian nearly as well as I speak it and understand the spoken word. The instructors were wonderful, native speakers all. But it is not cheap and it is tiring, since in private instruction you are "on" for two hours straight, no other students to take the pressure off. But I believe that's part of why it is so successful.

So for business, I'd go with Chinese but for pleasure (and to help me in fulfilling my pipedream of retiring early and moving to Italy) -- Italian. Of the four languages I can speak, Italian is by far the most beautiful for me to hear and speak!

Careful - "chais pas" for "je ne sais pas" is extremely rude. Funny in comics, maybe, but highly objectionable among civlized adults and well-brought-up children.

If you want to sound less than schoolbookish, abbreviate it into the perfectly acceptable "Je n' sais pas" - all in one, like "jennsaispas."

Among friends you can go one step further - "J'sais pas", still distinguishing the J sound from the s sound in front.

Now who said (in an earlier reply) French was monotonous? I'm stunned.

I have Rosetta Stone Chinese (Mandarin) at home. Was able to do the first lesson before I got caught up with work. From what I've experienced so far, I would recommend it. It might be frustrating at first because they don't translate (immersion technique instead) but you'll quickly learn a lot of words.