This one ended up being a simple build to keep the appearance clean and the machine as quiet as possible. The case is a slim CoolerMaster ATC 610-GX1 with a black annodized face. With the doors closed, it looks like a plain-faced stereo component. I used a giant Swiftec MCX478 heatsink with a low RPM 92mm to cool the CPU and another 80mm feeding it and the video card fresh air from above (no pic).
While it is the quietest machine I own, it is still a littler louder than I'd prefer for the living room.