The Hut are selling "Command And Conquer 3: Kane's Wrath" for the Xbox 360 for £14.93 (inc Del.)
You can get cashback through the usual sites (e.g. 5% Quidco, making it £14.18)
The next best price seems to be £23.00 from Zavvi.
***** Order Today (18th) after midday, and use the attached voucher to get a further 10% off! *****
Fight your way through an epic two-decade campaign told through high-definition video sequences.
-Choose from 9 Armies - Command powerful forces with unique units, superpowers, and all-new Epic Units.
-Control with Ease - Execute complex orders with a simple flick of your thumb using the all-new CommandStick interface.
-Prove your Worth - Do you have what it takes to survive the Xbox 360 exclusive Kane's Challenge?
-Show No Mercy - Nuke your friends in the name of Kane across 50 multiplayer maps.