I enrolled in a Japanese class last week. It won't do much for my professional or social life, and there's no plan to visit Japan in the near future. I just finally gave in to my obsession with Japanese pop culture. French and Spanish would be far more useful to me in Canada; learning either would be an investment. But I've never been the useful kind.
Curious George: Which new language would you most like to learn if given the chance? Why? ... sort of follow-up to this and this.