Knock Out Cosmetics new Flatte black nail polish is to die for. It's the first matte nail colour i've seen and it looks super sophisticated.
This new style has been created by fabulous New York make up artist Mike Potter (He did the makeup for far too cool film Hedwig & The Angry Inch, which if you haven't seen i suggest you amend that pronto). He apparently was sick of not being able to find any non glossy nail polishes so he went and created his own. It comes in a variety of shades but my money is down for the black and the Karen (which is essentially just red).
Available here http://koknockout.com/