What are some extracurriculars that are considered to be very impressive? As of now, all that I have concluded is that the following (research internship, governor’s school/rsi, columbia science honors program, starting a non-profit) are pretty good when applying to the top tier of colleges. And are there any competitions like USABO that you guys recommend?
I hope this is a joke, though unfortunately I doubt it.
The most “impressive” ECs IMO are ones that absorb you and to which you dedicate sustained time and effort for their own sake, while attaining a fairly high level of accomplishment. Trying to be impressive is not impressive (or if anything, is likely to make a negative impression).