I Bought an acrylic case for my Pi a while ago it was a great design - but it broke. I don't know why I didn't think of this sooner, but I ended up designing it so the exact case could be 3D printed. I made some modifications which made it better than the original. This will work with the Raspberry Pi B+ and the Raspberry Pi 2. The lid is hinged, so you can get at the pins without taking it apart.

I will be designing a bracket, to be able to stack these, since in my case, I have multiple, I would like to have them neatly stacked. Stay tuned for that.

UPDATE: This box also fits a Raspberry Pi 3. I've heard heat is an issue for the Pi 3s, so I've updated taller walls, a back piece with vent holes, and a new top to screw in a 40mm fan. These have the "Tall" prefix added to the filename. Lastly, I've added another set of plastic "pads" near the front, similar to the ones at the rear, so the front is no longer sitting on pins.