Comment Spanish, Brazilian Portuguese (Score 1) 514
Without a doubt Spanish and Portuguese (Brazilian) will get you a lot of options. Learning Spanish will make Portuguese a breeze and I have found a wealth of documentation in Portuguese for the development that I do. Spanish is also very useful so it will be a good investment--you can go anywhere and hear it and have the opportunity to speak it. Even if you do not get very far it will still improve your quality of life in the states and your vacations in the Americas. It's so very practical.
I'm learning Korean after learning Spanish and am still so very glad to have learned Spanish. Korean will consume the rest of my life and is only useful for a small percentage of the world's population... however, my wife speaks it.
Anyone that says you can learn Spanish overnight if you have to has obviously never learned to speak well, nor learned the intricacies of the Subjunctive or Preterite. I worked at a law firm as an interpreter and an interviewee came in and said that he would 'brush up' on his Spanish to help him get the job and I laughed to myself... How are you going to 'brush up' on what takes years to learn to speak competently in a Spanish speaking country? I will brush up on being a surgeon but might remove the wrong body part. People!
Have fun with it... and don't make it all about grammar.