I like the Adafruit's Raspberry Pi A+ Case for it's very compact and sleek look, but since I'm using my Pi as music player I didn't need all additional holes on it.
I removed ribbon cable holes on top and the large hole in the bottom. I also made the SD card slot bit smaller. I created one top version with no holes, and another one with few ventilation slots.
Since I'm working with SketchUp I've uploaded also the source SKP files if anyone wants to modify it.
My Pi fits nicely in it, and cable holes are large enough to accomodate connectors. Since walls are pretty thin power LED is visibly if you print it in light plastic.