I've always liked the idea of a pokemon mmo. Pretty much anything could be 10x better if you slap mmo on it
Granted they would have to change the game around a lot in order for it to work.
Another idea that I think would be amazing is if the game was a phone app that used google maps as the in game map. Businesses could be pokemon centers, poke'marts, gyms, etc. There are so many possibilities in that area