I've always had black iPhones (2G, 3Gs, 4, 4s and 5). For a change, I bought a white iPad Mini with retina last year and really like it paired with a white (well, light gray) smart cover. It seems kind of futuristic, like something out of 2001: A Space Odyssey. But this time I went with Space Gray on the iPhone 6 Plus (which I haven't actually received yet). I like the way the screen disappears on the black models when it's not turned on, making it just a black slate. I'm not crazy about the big black square on the ones with the white fronts. And it's true that black is slightly less visually distracting when watching video or playing a game.
But honestly, they all look pretty fantastic. I had written off the gold originally but after seeing it in person, I almost regretted not getting it myself. If I could cancel my Space Gray and get a gold today, I would. Looks classy IMO and not at all tacky like you might think.