I think its either City or Knight. Although in Knight, the batmobile kinda sucks.
I recommend playing them all. If you’re a Batman fan, you will love all of them!
Arkham Knight is my favorite over all.
I don’t like any of them, but I like aspects of all of them. Asylum has great atmosphere, but it is tediously repetitive. City has some cool settings and side-missions, but the controls felt too clunky for the game’s ambitions. Knight fixed every problem I had with the previous two games, but then it had to throw in that giant bar of soap that Bruce calls a Batmobile.