I'm surprised that there isn't a Forum just for the cash shop in general, but as the sale is on, I was wondering what people think is the best/most useful item they've bought from there? For myself its the 20% discount card, I save cash every time I use it, but I'm wondering if there are battle items I should be buying while the sale is on?

I always buy a few things I really want, and if I have some credits left after that I buy Ooh La Layers. They're useful and cheap. :)