You are extremely marketable speaking many languages. If you have a profiency for language and are willing to learn more that is wonderful in itself!
I have seen that many companies are looking for people proficient in Spanish, as it is very spoken prolifically especially in urban areas and is pertinent to many careers.
A good approach in deciding may be to look at some jobs posted that you may eventually be interested in and see what languages they require or are looking for. Many job listings ask for preferences. Even if you are not looking for a job just at this moment, exploring certain requirements and preferences may guide you in deciding what languages are best for you.
Obviously if you are diligent enough to learn many languages to pursue your goals being fluent or proficient in as many as you can would make you the most marketable for any career you choose! But that is a lofty goal! So I'd look toward a career your interested in and finding the language best suited to your ultimate goals.
Good luck !