I believe that all main (non-elective) subjects in school are important. My arguments for each are:
Math: We need to learn how to do mathematics in everyday life and for projects only done occasionally
Science: All humans need to know how the world around them works. I recently spoke to someone who didn't know how many natural satellites the Earth has. They know now, but it is still appalling.
English: We must learn to speak our national language fluently and without grammatical errors. This is simply because they make writing look sloppy.
History: "Those who fail to learn history are doomed to repeat it," George Santayana
Foreign Language: We live in a world where countries are far more interconnected than ever. Speaking another language helps people to be successful in that world.
I said MAIN subjects, math, science, English, foreign language history. If you think the only purpose of learning is to pass the test, it is just proving that there is something deeply wrong with our education system, or at least the one you have.