Buy one get one 50% off at Amazon

That's amazing.

It's really good under a couple key conditions:
1) You already planned on buying 2 games.
2) The savings add up to more than the potential Steam sale savings. (Ex: Buy 2 $60 games and pay $90 on Amazon for 60+30. Buy 2 $60 games and pay $80 on Steam for $40+$40)
Of course, the second point is just a potential event. Also, the Amazon deal only extends to 2 PC games: Skyrim and RAGE.

The fact that only Skyrim and RAGE are on the PC list makes this kidna crappy unless you do something crazy like buy 2 version of Skyrim then return the extra copy to Walmart for a store credit or something....