A complete bundle of XCOM goodness for £6.24 on Steam. Contains the base game with both DLC packs, and the Enemy Within expansion.
XCOM: Enemy Unknown
XCOM: Enemy Within
XCOM: Enemy Unknown - Elite Soldier Pack
XCOM: Enemy Unknown - Slingshot Pack
I realise that there's been plenty of cheap deals for XCOM recently, but if you haven't taken advantage of any then this is a great deal to get the lot.