I am an HR manager for a larger Danish company, so I may have a different view upon this. Well it depends.
Math.
This will make you able to control the most important part of your life. Your personal economy.
Physics.
This will probably prevent you from being a douchebag. It will also make you understand core factors of what we surrounds our self with. Like thermo dynamics. Linear movement and astronomy. The douchebag part is a reference to the friends we all have, that just don't understand physics. Those who thinks that stars are planets and that the moon are larger than the sun, since it's "bigger" in the sky.
Primary language.
This will give you the ability to be respected. You can lie about anything, but don't tell me you got an ph.d in Business management and economy when you don't know what the kuznets curve is. You have to be well informed, well mannered and be able to write properly in the language you talk (For me it's Danish). All this can you learn from your language subject. More importantly to be a critic against articles, and question their authentication.
Secondary language.
This is the most important factor of my life.
I come from Denmark. Without the ability to write, read and talk English I wouldn't have come to the place I am today. It is very important to have the ability to talk to the majority of people(I know that I make grammatical errors from time to time, but you still understand what I am saying). This is why I admire English speaking countries like the UK. Your primary language is English. One of the most wildly spoken languages in the world, and yet you (Sorry to say) are so ignorant not to learn one more? You have the best language foundation you could possible imagine.
In Denmark, we learn three languages as a standard. Danish, English and a language of our choice. Set the difficulty of these subjects and our understand-ability for the subject on a grade scale from A to F, where F is the lowest.
Danish scores an A. English scores an B and the last scores an D/F.
We don't really have to means and time to learn two wildly spoken languages, as Danish fills so much.
There are currrently just around 5.8 million people talking Danish. This is about 67% of the NYC.
I would love to be able to fluently speak English and Spanish. Then I would theoretically be able to speak to just about 60% of the human population.
I would personally think that a language skill-set comes over anything else in my current "important subjects". Strongly followed by math.
See it like this. There isn't anything worse than discussing politics with someone who says: I know I are a important part of today society.
This is far more annoying than talking to someone who don't know what a linear function is or maybe don't know that 60% of 50 is.