Space Grey...white bezel distracts from the screen too much.
Ditto. I bought a silver/white iPhone 5 because it's less prone to nicks and scratches. I prefer a black bezel. I feel that Space gray and an iPad in general is less prone to damage than a Slate phone.
I prefer the silver back, but the black face, so this was a tough decision for me.
Ultimately I went with Space Grey for my rMini. The white front is a little too feminine for me, especially on a small device like the rMini.