There are plenty of people printing all kinds of fun objects using 3D printers. If you have the right printer and know a bit about design, you can always 3D print your own PC cases. Take the Thermaltake Core P1 for instance. It is a 3D printed mini ITX chassis printed with PLA materials.
This video shows how this project was completed. The good news is Thermaltake is now offering a platform with 3D printing files for makers to come up with their own custom designs.