There seems to be several archetypes of characters that Jin Yong writes.
1. Beautiful, intelligent but unorthodox. Eg Huang Rong, Ren Yingying.
2. Generally beautiful, tragically evil. Eg Mei Chaofeng, Li Mochou, maybe Ah Zhi.
3. Beautiful, kindhearted, falls in love with a guy they'll never have. Eg at least half of the JY girls.
1. Upright. Eg Xiao Feng.
2. Upright and stupid. Eg Guo Jing.
3. Upright and not as stupid. Eg Zhang Wuji, Duan Yu.
4. Mavericks who are secretly upright. Eg Yang Guo, Linghu Chong.
5. The Bad Guy: powerful but not utterly despicable. Beaten by upright men. Eg Ouyang Feng, JLFW.
This kind of reminds me of Tolkien. I apologize for my short list; I have only translations to rely on. But it seems that Jin Yong uses archetypes a lot. Later on, he seemed to have elaborated more and blended roles some more.
Feel free to add onto this list, or list characters you think are truly unique.