Most sites have a creative badge icon instead of the simple circle. Some examples (from Android Enthusiasts, User Experience, and Bicycles respectively):
I think that Code Golf should also have a creative badge icon. What should it look like?
Speaking as a user, not a moderator.
I think Jin designs these for sites when they graduate. (I should ask him next time I have lunch with him.) Sure, you can provide input if you want, but I don't think they'll use community designs directly.
Update: PPCG is now undergoing design-independent graduation. We'll have most of the features of graduation, but the design will come later.