I wanted a case that didn't add much bulk but still provided a good level of protection. I picked up an Incase Slider for the 4S. I had one for my old 3GS and loved it. For the 4, i stuck with the free Griffin Reveal Etch I got from the Apple free Case program.
Once my orders from Lucky Labs and Graft Concepts come in, I'm hoping it will look like one of these two photoshopped mockups (I ordered both backs just in case).