#16 is very cool. I like the variation between the thicker and thiner lines.
I like how you changed #7 to #8 it's a simple change but it makes it work a whole lot better. Also, #11 works very well for me.
Number three and number 15 are very eye catching. I do not know if it is because they are in such a placement to accent them or if they are incredible by themselves, personally I'm more inclined to say the later.
I really like #3. The 1:1 ratio would make it work well. #10 also is really cool. the contrasting colorings and thickness of the lines work well.
#6 is my favorite, I think that it will be memorable if you add some color, I also like the zig-zag that ties the letters together in #16. You have so many great ideas.. I also like #14, how the two letters create each other. They are all versatile because of their simplicity.
I think that number 16 was the one that stood out the most for me. It seemed very creative and original. Although I loved all your ideas, number 16 seemed the most memorable to me.