Aliens: Colonial Marines is $30.80 at GetGamesGo with coupon code LV-426 applied at checkout. I know a lot of people are waiting on reviews, etc but thought I'd mention it in case anyone is planning on taking the plunge.
Go get the game, I hear that it's awesome!
GOG is going to release System Shock 2 tomorrow morning, no word on the price yet.
Also Dead Space 3 is good, despite the microtransactions and the Zerg-rushing necros all over the place.