I really like Carasibana's rack mount Raspberry Pi case. The original design is optimal in terms of ease of printing and side connector access, but if you want/need another configuration, here you go. I needed the network jack facing front, so I flipped it around. While I was at it I flipped it side to side, so you can mount it on either side of the rack, jacks facing front or rear, as desired.

Please post your makes and which orientation you chose and why.

UPDATE - Uploaded v2.1 front left and right versions which have a thicker rack mount tab to increase strength and rigidity when installed.