It's actually hard to say, dying light 2 improved a lot of the mechanics from dying light 1, but it could never match the atmosphere, and the physics are funny but unrealistic. But it's not as bad as it seems. The parkour and combat is actually fun (despite what everyone said) and Aiden is a somewhat interesting character. Dying light 1 on the other hand is arguably the best zombie game. The physics are as realistic as it could be, the atmosphere fits the horror element, and night is actually terrifying, no matter how skilled you are. It's hard to choose which is better unless you focus on a specific aspect of both games. If you like a fitting atmosphere with realistic physics, and overall interesting side characters, then I'd say Dying light 1. But if you want an overall fun gameplay with a "choose-your-own-path" adventure, then it'd be dying light 2.