A lot of people own Xboxs, but most of them do not know that their controller can be used on the computer. All you need to do to make it work is buy an adapter for around $6 shipped from ebay and download some drivers. The drivers support all the buttons, rumble, and even the slots on top for a microphone or something of that sort. A controller for the computer with all the features of an Xbox controller is very expensive, so even people without an Xbox can benefit from this!
To get an adapter, search eBay for "Xbox to USB"
To get the drivers, follow this link and click XBCD