2) Pokémon Diamond and Pearl
Without a doubt, the best new feature of Pokémon Diamond and Pearl was the addition of the ability to trade and battle online. While FireRed and LeafGreen came bundled with a wireless adapter, these were largely the first games that properly took advantage of not having to be shackled by to a link cable to enjoy Pokémon with a friend.
It made the journey of catching an even higher number of Pokémon a whole lot easier and finally meant that we wouldn’t need to buy both versions of the game to catch ’em all!