The Xbox 360 wired controller is supported on all operating systems.
Should work out of the box.
CONTROLLER (XBOX 360 FOR WINDOWS)
Should work out of the box, but note that the button mapping can be wrong if you are running an older release of Linux, in which case you must create a custom config.
MICROSOFT X-BOX 360 PAD
Mac OS X
Requires a custom driver to be installed. This driver can be downloaded here: http://tattiebogle.net/index.php/ProjectRoot/Xbox360Controller/OsxDriver