I know this could be applied to lots of purchases and requires opening up the Amazon credit card so restricts some, but still a great deal.
Disney DVD and Blu Ray on buy 1 get 1 free at the moment, two Blu Rays for £16.98. Open an Amazon credit card and get £15 credited to your account, bringing total to £1.98 for 2 Blu Rays delivered.
Just bought Bolt and Wall-E for the kids, Bolt is a Blu Ray & DVD combo pack so even more of a bargain!
Sure this will get voted cold, but be kind, only my 150th post ;)