Depends what you mean by 'work right'. There's plenty of pads which get correctly identified and installed by the kernel, e.g.
http://www.qbik.ch/usb/devices/searc...p?pattern=game
If you have kernel source there is some further documentation in Documentation/input/joystick.txt. But then I don't know how you would go about configuring it for a particular game or app. I would think the application docs should give some advice. What's the mapping software you are using?
There is also a driver for the X-Box gamepad, but you have to get an adapter, or replace the non-standard X-Box USB plug:
http://www.dangray.org/index.php?id=...t%5Blang%5D=en