Rob, As soon as I saw the pictures I knew someone would suggest cropping #2, which, incidentally, is the best of a very good lot. And Peter didn't disappoint me. Don't even consider cropping it. The horizon is exactly where it should be: near the center of the picture. A centered horizon gives a feeling of stasis (equilibrium), which is exactly what you want in this minimalist shot where, incidentally, you can tell the normal direction of the wind by looking at that single, exposed tree. I also like #4 very much. It's sort of a German version of Walker Evans's approach to towns and cities.
Good shooting, and welcome.