Hi Stickie,
You have done a lot of work! I like them because they are strong and simple. The X's differ, in # 21, 20, 15, and 11 it looks a bit like a spaceprogram.
I like the fimness of your designs, but I do not see my logo yet. Someone turned the X into a person, which is my main objective in my work (persons, or people). I liked that because it has a certain relevance.