The Humble WB Bundle
includes a lot of goodness for a low price.
Right now (2013-11-05 18:19EST) the price is less than $5.00 to get all of the games, including:
Batman: Arkham Asylum GOTY
F.E.A.R. 2: Project Origin
Lord of the Rings: War in the North
Batman: Arkham City GOTY
For the first four, pay $1 or more- to get the last two in addition, pay more than the average. And all include steam keys.