Just a small machine for some light gaming. I had a Dell so I salvaged the Processor, RAM, HDD's, Optical Drive and Graphics Card from that. I'm running a minor CPU overclock at the moment because a have a non-K processor but I still wanted to tinker a bit.
EDIT: I just bought and installed a Sapphire R9-280X Vapor-X. It is really good. I was a bit concerned when I read some reviews and they said that it could be noisy, but I can't hear it at all really. My case does sit under my desk though, so that probably contributes.