With the iPhone 7, I went with the gold. Which I really like with the white bezel. In the past, I've always gone with space gray with my SE and iPhone 6 and 6s Plus.
I really want silver, especially for the white bezel, but none of the colors with white bezels hide the antenna lines very well so I went with jet black. Still beautiful and I don't regret getting this one at all, but I miss white.
Upgraded from the 6 to the 7+ in matte black. I'm annoyed to no end with the white faces and gold/silver backs.
I like color uniformity in my phones -original iPhone being an exception. The matte is 100, the jet black is, but I hate scratches so matte black it is.
My wife went with the pink and I went with the white iPhone this time. After having black iPhones for awhile I decided I'd try white - at first I liked it because I think iOS 10 works with a white theme. However, I miss the black. So for my iPad Air 2 I went back to black and I think I prefer it.
7 in black, I wish I'd gone for the jet black, it's less slippery so could use it without a case! I don't think the scratches are as big of a deal as anticipated