I think the straight down the lens look has a more intimate feel. The averted eyes appears more natural although img.F80A0698 where the head and body are turned slightly away but the eyes are looking at the camera looks pretty natural too.
I am not too sure which I prefer but I do like the natural looking portraits better - whether looking at the camera or away. I suppose it depends on what kind of 'feel' is intended. With the body facing straight at the camera it looks bigger and gives a more aggressive or defiant impression, turned slightly away and it appears slimmer and less intrusive. The direction of the eyes and the angle of the chin is also important, the chin tilted slightly down with the eyes looking up can make the eyes appear bigger but if the chin is tilted down a little too much then the pose can be submissive.