Nicole Richie's House of Harlow 1960 sunglasses are available at Kitson. I really like them because they're quite Jackie O. Richie has been seen sporting them (see above photo). It cracks me up that they cover half of her face.
I've been wearing shades with a slight cat-eye, but I'm always a fan of an oversized pair. These black-and-gold glasses have gold double H logos on the temple. They're $125, which I think is pretty reasonable for sunglasses. Kitson says they're "masquerade mask inspired." Hmm, I guess they are about as big as a mask.