4. DexNav
The Habitat List was also introduced in Black and White 2 (it seems like most of the best features did in hindsight) and then greatly expanded on in the Hoenn remakes into the DexNav system. This system basically lists all of the Pokemon you can find on any given route and grade you accordingly so you can keep track of what you need to catch and where they live with relative ease. In addition to this, the DexNav introduced a system where you could chain Pokemon to get higher IVs, egg moves, hidden abilities and even increased shiny odds if you were patient enough, making it the ultimate system to find rare Pokemon with the best abilities.
5. Following Pokemon
Although technically introduced in Yellow with Pikachu, Heart Gold and Soul Silver is where this series saw its full potential with every Pokemon in the game being able to follow you at any time, giving you a close and personal bond with your team members and adding to the overall immersion. This feature was brought back in Let’s Go Pikachu and Eevee and recreated beautifully with every Pokemon having unique animations whilst following. Even giving the ability to ride select Pokemon as a means of faster travel through the region was added. This was brought back in the Isle of Armour expansion for Sword and Shield but it feels quite undercooked compared to how Let’s Go managed to implement the feature, especially as you can only do it on the island.
6. Mega Evolution
One of the best gimmick features to be added in recent memory, Mega Evolution was the leading element in Generation 6 stories and competitive scene. A temporary transformation, 48 Pokemon were capable of this temporary transformation making usually nonviable choices see the spotlight and create new team possibilities. Although a little unbalanced at first, Mega Evolution was adjusted and correctly balanced in Generation 7 but is absurdly absent from Generation 8. (likely to not take the attention from the new Dynamax feature) The return of this feature would make long time fans very happy and allow weaker Pokemon with the trait to return to their former glory!
7. Rematching Gym Leaders
This is as simple as it sounds. In every game the post game should allow you to battle the regions gym leaders with beefier teams and more intelligent AI. This feature almost always seems reserved to remakes or in some rare cases definitive versions like Platinum but it should seriously be a series staple at this point.