The first nude is intriguing, but it looks very stiff. This shows up most prevalently in your hands.
The second one has an interesting concept, but I'm not a fan of the lit face and dark body. A little spill, or more play with the shadow would have been more interesting. Not as much about you as the photographer.
I don't like the silhouette. There's nothing particularly intereting about the forms generated. It looks more like an accident where the photographer missed his exposure.
The fourth is my favorite. It's nicely posed. Well lit. The only thing off is the composition. Overall the best of the four.