Aside from reiterating what everyone else has already said regarding grades, I think the important thing to remember is to be open to ALL of the groups on your campus. It may seem callous, but this is true: By choosing one house prior to recruitment that you are "set" on, it can set you up for a disappointment. (Note that I said can and not will here, I don't want anyone to think that I am being mean, just truthful.) Not everyone gets their first choice for one reason or another, whether it be grades or something else entirely, and people's feelings about chapters may change once recruitment starts. As old and reused as this sounds, some chapters may surprise you, especially the ones you don't know a lot about.