I like the Black front of the iPad. It looks like a complete black slate when it's turned off. That's why I got a black one again. My iPad 2 and 3 were white, I got the black Air and now the black Air 2.
White. I had a black air but I'm tired of lint, dust, fingerprints, scratches, and particles getting stuck in the bezel. I don't want to worry about having to keep it clean looking all the time.