I just bought a case on netonnet for my Raspberry PI.
Raspberry RPI-BOX1 (netonnet)
The RPI fits nicely into the case and snaps to the bottom of the case.
The top of the case snaps on. I think it looks nice and feels well made. The disadvantage is that the GPIO is not accessible with closed lid and the leds are not easily seen. All the external connections are accessible.