This deal has ended.
Update: this is now $49.99 plus $6 for shipping. Buy.com has the best deal yet on the Xbox 360 Wireless Controller: it is $47.99 but only $37.99 if you pay via Google Checkout because of Google $10 off $30 promo. Also, if you spend $50, the discount jumps to $20. Plus, shipping is free and there is no sales tax. Overstock (no longer available) had this at a similar level below $40 but the option of getting the $20 off makes this much better. Everyone else in the world is paying around $54 after tax at the local BestBuy.