I have just used the £23.50 off at Littlewoods code to order Forza 2 for my other half who almost bought it in the shops the other day for £40.. (When will he learn!) :-)
So it works out as £50 - £23.50 = £26.50 (using code ZQ055 - Existing customers can use this code)
This is the cheapest way I can work out to get it, unless you do the Blockbuster deal I read about. Unless like me you don't have a blockbuster or the time. I think this is a fair deal!