Urrrm, that is a difficult one but I would probably say my custom embroidered wrap from Wee Notions. It is pink fleece with candy stripe binding and a flower embroidered on the bum. I will take a piccie when I remember and post it - it is lovely.
A close second is my new custom wrap from Cat - a gorgeous Winnie The Pooh fabric.
I can understand getting into buying wraps, I tend to buy wraps more than nappies - after all it is the bit people see. And now that Charlotte has moved into large sizes, I feel I can justify it more as (I hope) these will last her until potty training.