The answer is always regrowth if you want a challenge where if you do it right you can actually see the impact of your playing changing the world from a barren wasteland to one that springs new life everywhere. The counter to that is of course B-Team where everything is upside down.
Ozone 2 kappa - or any other pack with few challenges like get every armor you can get on this pack and make display room, get every block of metal avaiable etc.
