Microsoft Spain have beaten Major Nelson to the punch with the announcement of the Games With Gold titles for March that Xbox Live Gold subscribers can download for free.
If you have an Xbox One, this might be the best month so far in terms of value with the detective game Sherlock Holmes: Crimes & Punishments free all month and starting March 16 until April 15, the beautiful Dark Souls inspired RPG Lords of the Fallen is free.
Between March 1-15, all Xbox 360 owners can download the strategy game Supreme Commander 2 and March 16-31 Borderlands is free. But keep in mind that you can also download these for Xbox One thanks to the addition of backwards compatibility.