I wanted the smallest case possible for the Nexus, as a lot of the generic leather 7" tablet cases add a considerable amount of bulk to what should be a slim device. I settled on a Poetic Slimline Portfolio case and have been happy so far (
http://www.amazon.com/gp/product/B008NMCPTQ). I also have a Timbuk2 sleeve for when I want to use it nekkid, but keep it protected in my bag.