Are you so blind and deaf to the appeal of first-person face-shooting that you've disregarded the Call of Duty franchise up till now? The latest Deal of the Week, sir or madam, is for you. Microsoft's chopped up to 50% off the price of every single Call of Duty game on the Xbox Games store (hitherto known as the Live Marketplace).
As always with these offers, you might get a better deal by rooting around in the bargain bin at your local retailer. Or, if you've already put yourself through Call of Duty's threshing mill several times over, you should check out this NeoGAF post for a range of additional discounts, some doubtless dependent on region. I may write a few of them up later on - there's an unusually fearsome selection.
Call of Duty: Classic - £6.69
Call of Duty 2 - £11.99
Call of Duty 3 - £11.99
Call of Duty: Black Ops - £26.99
Call of Duty: Black Ops 2 - £33.49
Call of Duty 4: Modern Warfare - £14.99
Call of Duty: Modern Warfare 2 - £19.99
Call of Duty: Modern Warfare 3 - £24.99
Call of Duty: World at War - £14.99