My turn to weigh in!
I always thought the AOII pin was really pretty. Especially the ones with the "chased" letter 'O'.
Kappa Alpha Theta also has a nice one.
Kappa Kappa Gamma's key is unique yet well designed.
Three that I think deserve more recognition are:
Sigma Kappa's maroon enameled triangle with the *scrolled* edge. The regular one isn't that impressive, but the scrolled edge badge is very well done.
Alpha Xi Delta's Quill is very elegant. For some reason, I seem to be partical to the unjewled version.
Alpha Phi's unjeweled badge has a simple attractiveness to it.
An honorable mention goes to Phi Mu for the quatrefoil design. I've seen them on eBay and they have some very nice jewel combinations.
Of course, I could probably list them all with their respective qualities!
......Kelly