Irrational Games is giving the PC crowd extra incentives to purchase BioShock Infinite. On Steam, they're doing that whole rewards unlock thing where the more pre-orders come in, the more free stuff will be given out.
At the base level, you'll get the Industrial Revolution Pack for free. At reward level one, the original BioShock will be given to players. Reward level three will get you X-Com: Enemy Unknown. At reward level two, players will get an exclusive set of Team Fortress 2 items (all detailed below.)
Green Man Gaming, on the other hand, doesn't "believe in 'unlocking' pre-purchase offers" as stated in an email to subscribers, and their deal is way more direct. Pre-purchase BioShock Infinite from them and you'll instantly be given the original BioShock, and your choice from one of these 2K titles: Spec Ops: The Line, Sid Meier's Civilization V, BioShock 2, The Darkness II or Mafia II. You'll also be given a choice between $15 GMG credit, or $14 cash back.
Lastly, Amazon will throw in $30 in credit that can only be used on 2K games, BioShock Infinite: Mind in Revolt for Kindle, and the Industrial Revolution Pack for pre-orders.
Have to say, the GMG deal is killer. Unless you're addicted to Team Fortress 2 and collecting all the hats, GMG is the way to go here.
The BioShock Infinite Team Fortress 2 items:
The Pounding Father
The Person in the Iron Mask
The Sydney Straw Boat:
The Steel Songbird: