#18 is our favorite of your first three entries. The radiating lines above the letter i should be rounder, not so elliptical. Also, try using this element above all three letter i's. Also, try making the letter i shorter so the dot sits lower.
For #19 and #20, we like the dots on the letters i, but do not like playing off the letter for the graphical element.
For #25, we suggest the following changes: The color should be more red, the red lines should be thinner, and the outer lines should be less saturated.
#26 - looks good, but we do not know how this relates to us.
#61 is heading in the right direction, however, the dot should be the darkest color and the color should fade away in each of the other two arcs. (Get's lighter as you move away)
untung. Thank you. please take a look at this: https://dl.dropboxusercontent.com/u/1494821/CiviLogo/civi02.jpg This is a very quick hack to give you an idea of what we would like to see. Do not take the linked image literally. We are just trying to get the idea across - you are the artist and you should make it look good.