Xbox 360 Wireless Controller for Windows and Xbox 360 for $19.99. Shipping is $4.99 so the total comes to $24.98 shipped. It works with both Windows and Xbox 360 and has a built-in vibration feature. As comparisons, Overstock has it for $54 and Best Buy has it for $62.
This deal has expired. Congratulations to those who were able to get in on it.