These are my own considerations. I don't know if you have any special attachments to these languages.
My advice would be to scratch Latin off your list, unless you are planning on becoming a priest.
Because you grouped Greek and Hebrew together, I'm going to assume it's for their biblical usage. If I'm right, I'd scratch them off your list right now. I'm not sure why, but the majority of people exploring a second language flock to these two; I did. (They rarely go very far before being dropped.)
It's estimated that the number of people who can use Esperanto fluently is between 100,000 and 300,000. "Small" minority languages like Welsh and Catalan have ~700,000 and ~7,000,000 speakers respectively. I think the idea of Esperanto is neat but not enough people speak it. The majority of esperantists probably speaks English, Chinese, Korean, or Japanese too. Scratch it off the list.
Now you have three to choose from: Korean, French and German.
Korean could work because you seem to have an affinity for the Far East.
French is probably the easiest language on your list to learn and has the widest geographical range.
German is also good and is the most spoken language in Europe, I believe.
@gnunix: I heard the average Japanese video game takes three times as long to translate into Korean as the next longest language translation period.
I hope my semi-colon and colon usage is to your liking.