>>20978613IMO, making it more like diamond and pearl again, and go further. Villains that were actually threatening, multiple colorful/fun recurring characters, a rival that logically matches Ash's level, Ash's companions get a lot more development, they reference past things in the series (Misty's lure, Ash's aura etc), probably some other stuff I forget.
One thing a lot of people don't seem to understand though, is that you can't take away the monster of the week formula the show has, because it's likely even the people making the anime have no idea how long a series is going to last, so any sort of overarching plot would have to be presented either as mini-arcs (what BW did with Plasma) or as little teases early in a series until later on (what DP did with Galactic). I personally prefer the latter, but it might be because of how bad BW turned out.