PC players can download the excellent Assassin's Creed: Black Flag for free next week, as part of Ubisoft's Happy Playdays seasonal promotion.
If you fancy downloading the rip-roaring, piratical high seas adventure (which I still reckon is the best Assassin's Creed game, but then I'm easily swayed a peg leg and a palm tree), it'll be available between Monday December 11th and Monday December 18th.
If you're after a more immediate freebie, however, Ubisoft is also giving away a PC copy of alternate-history RTS World in Conflict, plus its single-player Soviet Assault expansion, right now. You've got until December 11th to grab it.
Both games can be downloaded by signing up for a free Uplay account (if you don't have one already), then logging into the service and following the extremely prominent banner. More details on the current offer can be found on the Happy Playdays promo page.