I must say my fav. September item would be the Superior Form. I've always wanted it but, couldn't afford it. I think it's great with the skin colors because then, I could dress my avi up like Cheetara from ThunderCats my fav. anime with the leopard spots. The robot metal one is neat too. Then it would open up the possibility of my avi being an android.
Superior Form(September 2007) is a really nice avatar item that can make people into a cat, robot, doll, dragon, or flaming inferno. This opened up new possibilities for aesthetic purposes and creating an online persona for role playing purposes.
Probably not unlike the rest of Gaia, my favourite September MC is the Mini Angel Wings, though the Mini Nitemare Wings are also appealing. Although I do not own a set of either, the Mini Wings will always hold a special place in my heart because September 2003 was when I joined Gaia.