I hadn’t noticed @bomerr’s push toward school led ECs. Again, this could not be farther from the correct path, especially if you are shooting for top schools. A unique EC that expresses your interests and where you accomplish something significant far outweighs any school based activity no matter how well you do at it. The key to admissions to the very top schools is strong academics & test scores, but also branching out into something unusual in ECs and doing it very well. Team captains, valedictorians, newspaper editors, etc are a dime a dozen in top college admissions. They literally see thousands of them in the HYPS pool. What turns their head is something where the student took initiative and did something new.