Thinking about the responses you got to your question would be a good start. DadTwoGirls already gave you an opinion about ECs. Others had very good posts too.
Instead of focusing on what ECs might make you competitive for a top 25 school I think you need to focus on why you want a top 25 school to begin with. Going to a top 25 when you want to go into medicine isn’t going to impress anyone and, if you don’t graduate with a stellar GPA, you may have trouble getting accepted to med school. Look for colleges that will help you meet your goals.