What subjects at high school should i take if i want to be a physicist?

As much math as possible, as high a level of a physics as you can get into, and computer science. Other sciences help as well, especially chemistry. Most physicists will need to know how to program at some point, and if you pick it up before grad school, all the better. It will come in handy if you do an REU (research experience for undergraduates) in college (and you should do several, if possible).