I love the simplicity of Calvin Klein's designs. Eventhough they are simple, but I think they still have a lot of "omph". Just like a couple of these pics below, you can dress it up and you can dress it down.
And I always love Versace, I love how a lot of the dresses have very interesting back. Like this piece from Haute Couture Spring 2008, don't you just love the back of this dress?!
Those pieces are really inspiring to me. Now let me just go back to my sketching paper and sewing machine :)