Back in the day I thought it was red/black avis. Theres so many items now it's too hard to pin one item as overused. People say the lusty scoundrel skin and cloud slippers are popular, but I've actually never seen anyone in the forums with the slippers and very rarely the scoundrel skin.
I don't think this is really a big thing on Gaia anymore, because the lack of diversity in items. Back in the day everyone and their grandmas had penguin and seal slippers, gaia shirts, grass skirts, nitemare bustiers and headbands.. those were like the "it" items, I don't feel like it's like that anymore.
Outside the GCD, I see a lot of avatars that resemble something like this:
This is most likely due to the increase in Band of Bremens, the new release of Rosamund's Redemption, and the popularity of the leg mod from Keiko's cake. Even I had an avatar that closely resembled this.^^; (See my sig! XD)
The Ciel tems are ridiculously overused and abused, but admittedly I'm one of the abusers. xd
I have all of them except for the new white one. I'm waiting to see if the price drops before I buy it. They're just so gorgeous! Other than that, Band of Bremen. I'm also one of the abusers. Keiko's Cake? I also caved into that trend. I don't really care that they're overdone; if I like it I like it.
I'm a big mass of overused right now, but I just really felt a strong desire to be "cute." My last couple avatars have dealt with the Eototo Kachina Mask (which I still love <3), so it's odd to see my face in all its glory.
I was just about to say the Steel-plated Ninja Band. Definitely.
I've seen some otherwise very well put-together avatars that are just completely ruined with a ninja band. Why the ******** is it there? It's like it's there just to be there. It doesn't add any aesthetic value to an avatar in many cases and, in fact, may deter from it because it's just so far out of left field. It's like someone needs that one rare/expensive item to show off wealth and they decide that's gotta be the one.
No matter how ungainly it looks or how much it doesn't match with the rest of the avatar.