5) Just Cause 3
This is the most recommended DLC's for Just Cause 3
Air, Land and Sea Expansion Pass Link
Sky Fortress Pack Link
Rocket Launcher Sports Car Link
4) Fallout 3
If you get the Game Of The Year edition of Fallout 3 you get all the DLC's, so instead bellow I will show you the best mods
Iron Sights Mod Link
Weapon Mod Kits Link
Enhanced Weather Link
3) Project Cars
This is the most recommended DLC's for Project Cars
Aston Martin Expansion Pack Link
Old vs. New Car Pack Link
Japanese Car Pack Link
Renault Sport Car Pack Link
US Race Car Pack Link
2) Dirt Rally
Since this game has only been released there are no DLC's or full mods for the game except some car liveries.