The best recommendation I can give is simply to get Gamepass. Not only are Halo 5 and MCC, Gears 4 and 5, and Forza Horizon 4 on there, but literally hundreds of other games, many of which are great.
But for more recommendations that were console exclusive to Xbox that you will have missed out on most likely: Sunset Overdrive, ReCore, Quantum Break, Crimson Dragon, D4, Killer Instinct, Halo Wars 2. Some of those are on Gamepass, others are not.
Thanks for the recommendations! I'll definitely try out Gamepass as soon as I get the console!