Uncharted 3: Drake's Deception DLC across PSN.
Uncharted 3's single-player campaign has been knocked down to $25 for a download, which is the price of a physical copy through Amazon, and all of the multiplayer DLC map packs are available in one bundle for $18.
The free-to-play version of Uncharted 3's multiplayer has a level limit of 15 right now, but if you want to raise that to 25 you can do so this weekend for $3. Otherwise, spending $12 unlocks unlimited leveling. Both the Adventure co-op add-on and Arena co-op add-on are priced at $8 and $6.
This sale will conclude on Monday, July 29 at 12pm PT, at which point everything will revert back to its full price. To purchase any of this content, simply head through the Extras menu within Uncharted 3.