>Gen 1
Gave us nothing but nostalgia
>Gen 2
Gave us held items, breeding, shinies and 2 new types.
>Gen 3
Gave us abilities and berry farming.
>Gen 4
Gave us Physical-Special split and Wi-Fi battles.
>Gen 5
Triple Battles
Rotation Battles
Rare Wild Battles
Hidden Abilities
First game to have fully animated sprites during battles, not just intro animations
First game to have full back sprites
First game to have a dynamic camera in battle
First game to get a direct sequel instead of a third version
First game to have fully 3D environments
Gen 5 gave us the ability to reuse repels without going back into the menu
>Gen 6
Gave us a new type, mega-evolutions and was the first mainline game to transition to 3D and provide 3D models for all Pokemon.
>Gen 7
Gave us totem battles, SOS battles and z-moves.
>Gen 8
Gave us dynamax and overworld Pokemon