I will say its Gears 5. Coalition has been incredible with their usage of Unreal since the original Gears of War back in Xbox360 days. They peaked with Gears 5.

The original Gears was developed by Epic and was a very good showcase (and probably a driver and validator as well) for the Unreal Engine tech Epic developed in parallel.

They describe how this is still their dynamic when they mention their goal to have Fortnite running on UE5 before they consider it ready for the masses.