Thing #2: "The Lingual Thing"

Okay, I'm ready to declare my second challenge.  This Thing's pretty straightforward...but I do need a little help from the blogosphere with this one:

Thing #2 (aka "The Lingual Thing"): Learn a new language.


I completely understand that this will be a tall order for one year, but my goal is simply to make as much progress as possible.  But, the big question is...what language?  Any thoughts out there?  Would love to hear suggestions and rationales.  The sooner I decide, the sooner I can get started.