We like
#62 a lot. The added depth is nice and the shaded square make it clear that it's a cornerstone. Some font/color variations would be appreciated. I don't think that that the dark letters would show up well on dark backgrounds, and I'd like to see the font without the horizontal light shading line at the bottom of the letters.
Also, could you reverse the graphic so that is slant up from left to right instead of down?
Nice work!