White, by far.
I just went to BestBuy to check out the phone since I am on Verizon and wanted to compare the colors.
Originally, I had preordered the black because a few reviews said that it looked nice or even nicer than the white model.
However, when in the store the white looks quite a bit nicer. One of the reasons a lot of people get black is because they feel it makes the screen colors "pop" more or are more vivid. This may be true--but the black versions face has that glittery textured look.
Because the black version has this look and its much more noticeable than the white it is actually distracting and takes away from the screen. Especially in bright light or in the sun it would be even more distracting.
The white version also has a similar textured diamond face but it is much less noticeably glittery / shiny reflective front and back and looks better overall. This diamond pattern actually gives the white version a nice pearly look on the back and is not distracting from the front. The white model also seems to "stand out" more from the crowd and doesn't seem like just another black phone.
As such, I called Verizon and had them switch my preorder from black to white.