Forza 7 & Vermintide 2 free weekend with gold.
Forza is a real looker on the X, and a gigantic download. Playing it can boost your Forza rewards tiers. Might be some kind of loyalty bonus with Horizon 4 soon.
Vermintide 2 is also in gamepass and can be finished in ~ 10hrs. Save Sienna for last if you’re trying it solo. Using the other characters improves your bots.