Princess Luna, in her majestic human form. This is how I see her. This is how I dreamed about her (really, I did... in a very weird Ponies-meet-Skyrim setting... there might have been some Dragon Age mixed up too <_<).
All hail the true Lady of the Night!
and yes, I know I'm having problems with human body. Ponies are easier I had to use tons of references, especially for hands and, surprisingly, breasts. One would think that breasts are easy to draw...well, they aren't.