[EricVanWyk]

The DS theoretically supports any USB device that conforms to the HID Joystick class spec. Many (most?) joysticks and game pads comform. Try them and report back if they work.

As a general rule of thumb, if the joystick/gamepad requires extra drivers to be installed, it won't work (the DS doesn't have those extra drivers). For example, the xBox controllers don't work.