@perspectivestude generally speaking, grades are most important. However, you can look at the Common Data Sets for the colleges you are interested in to see how important each factor is to them.
For example, here is the Common Data Set for Washington U:
https://wustl.edu/wp-content/uploads/2014/09/wustl-cds-2015-2016.pdf
If you scroll down to page 7, you can find the answers you are looking for.