Mine were DG and AEPhi. And I guessed from about Day 2 which chapters they were in. They didn't give anything away--but their personalities fit their chapters well.
5 of us from my Rho Chi group went DG (1/4 of my pledge class!). Our DG Rho Chi was a senior when we were freshmen so it was sad to see her go--but it was great to spend time with her after recruitment (as she held back her 'wild side' until later
).