Quantum Break.
You can find out more why in
my review, but for some extra context, before this game, I did not have a favorite game.
I don't think of myself as one to have favorites, but Quantum Break is what made me realize that something doesn't have to be the "best" to be your "favorite".
I still absolutely love other games (like Titanfall 2 or CoD: IW) but Quantum Break is undoubtedly my favorite