Just in time for the holiday season! Kill some Nazis in one of the best RTS games of last 5 years. Go ahead and grab your Steam key by going to the Humble Store page.
GOG is offering The Witcher 2 for free - a game made by the development arm of its parent company CD Projekt - but you have to collect stamps each day by visiting the site in order to claim it. Seven stamps, seven days, claimed by clicking 'collect stamp'. More info on GOG.