I am part of a local sorority so my fav. national sororities that i tend to root on at events and have friends in are Phi Sig and ADPi. SOme are in Sigma Kappa too.
Fraternities... hmm... that's tough... cuz there are a few i like. ZBT is cool cuz they are smaller and I have a lot of friends in that colony. Delta Chi is good too cuz without them... I wouldn't have a sorority
But Sig Eps are nice guys all around.