Sunglasses!!
It's a little of a splurge to pay full price for a pair of say, Chanel or Dior. And they don't go on sale often. So with a nice gift card "discount," I say go for it.
I got a pair of the Denise Richards Chanel sunnies with the gift card I received after splurging on a Chanel jumbo flap bag.
Good luck!