Killing Floor: Complete Pack (75% Off)
Price: 9.99 (75% Off)
Nobody does thematic content quite like the guys at Tripwire Interactive. It seems like every season they're releasing a new update for Killing Floor with all sorts of new levels and enemies for you and your buddies to face off against. The latest pack, called The Hillbilly Horror Event is full of redneck zombies and ghouls for you to take a buckshot to.
While every piece of content for the game is individually on sale, the complete pack is by far the best deal. You're getting 11 DLC packs, plus the full game for under $10.