Good ideas above and wanted to comment on them. In general, ECs don't matter for residency in the way they did for medical school admission. Like noted, everyone has some basic stuff. What is KEY is to remember that ECs will not make up for a less than good Step 1...so don't extend yourself to the detriment of your coursework in the misguided belief that you have to have ECs for residency.
But beyond academics and things like "good fit" or great personality, these are a few things that will make faculty member's perk up:
- Spanish speaking - FLUENTLY; in areas with a significant Hispanic population
- Published research, as first or second author
- Nifty stuff, like being a former Olympian or race car driver or supermodel
- When you know a friend or colleague of mine and there is an LOR in your file from them
Otherwise, I don't really care if you were a member of the Surgical Interest Society (even if you were president), Class President, volunteered in Rwanda (sorry, yawn...its getting old hat), ran the Susan Komen Race for the Cure every year or built Houses for Humanity.