Bioshock Infinite's season pass is an essential purchase for series fans and the £3.31/$4.99 price-tag is one of the best prices we've seen. Yes, this is on a Mac store, but the download is PC Steam compatible.
The season pass includes the excellent Burial at Sea episodes that sees you playing as Elizabeth in the infamous underwater city of Rapture. For series fans, it's just pure gold. You can read my review of Episode 2 here. The pass also includes the arena DLC and a few in-game bonuses for the main game. The main draw though is this unique trip to Rapture in it's prime before the splicers ripped it apart. Chilling and beautiful in equal measure.
Thanks to jaystan.