Ni Ni Kuni: Wrath of the White Witch is a already paid off, day one game for me. I'm also going to pick up Life of Pixel, just to help the developer fund his other games.
There is a 50/50 chance for EDF, Hitman HD and Ratchet and Clank: FFA
If you want to update the OP with a list of games that are coming this month. Just omit Sniper Ghost Warrior 2.