Alphonse Mucha

Zodiac 1896: The zodiac symbols forming a circle around the head are eye catching.
I like the continue theme of circles throughout the image.

Bieres de la Muese 1899: Mucha's ethereal quality is extremely appealing, specifically in this image. The smaller pictures the woman is leaning on is a good concept, especially during the time period this was created.

Maud Adams as Joan of Arc 1909: I like the use of pastels and the decorated border in this image.

I'm also fascinated with the expression on the woman's face and the semi-transparent face above her.