Images from Polyvore.
Just judging by the pictures, the colors both look very close to the Tiffany Blue color. The Chanel version seems to have just a little bit of shimmer, while the China Glaze looks pretty solid. However, the Chanel nail polish usually costs around $23, while the China Glaze sells for about $3-$6. For that much of a price difference for such a similar color, I am willing to sacrifice the shimmer. As for the quality of the China Glaze, I will let you all know :).