Chinese, or at least one of scandinavian, because there's a need in a job market for scandinavian languages (at least in europe) and china is huge economic player right now, so knowing their language would pay good money.
Arabic and Spanish. Because is interesting for me and I am thinking to move to Spain
German
Russian
Russian, because it is useful in baltic countries
Russian because lots of people are using this language in foreign countries due to understand each other.
Chineese because it helps me in future to have a good job. Moreover, amount of people speak Chineese.
Greek and Latvian, because I have a lot of friends from these countries
None, i love Poland, only Poland!
French, Spanish, Russian they are used a lot in the world.