Have used the code XX214 for 20% off. The xbox 360 Arcade is being sold by Littlewoods Direct for £159 which is an okay price for a catalogue web site (Littlewoods, Choice, Great Universal all overpriced at £199) add in the 20% discount and this = £31.80 off + £3.50 postage = £130.70 delivered. The good thing is that the code appears to work for existing customers as well as new customers which is not usually the case.
I know there has always been some question about these codes being honoured by the retailer. All I can say is that I have used them off and on for some time now and never had one rejected yet. Oh and I know you can add codes for free delivery but technically you are only supposed to use one with any given order and I dont want to push my luck for the sake of £3.50 !