This is just for me, and I speak for nobody else but myself. Make him more like his AG self, mature but he knows how to have fun and inspires trainers the right way. Give him new Pokemon. I'm sorry but I am sick of Grass, Fire, Water, and Flying Pokemon every region. It's worse when they are the Starters. More creative teams. Have a Poison, Dark, Dragon, Steel, and Rock Pokemon one region, and then next region have a Grass, Flying, Ghost, Psychic, hybrid Pokemon the next. With so many Pokemon types, it's boring to see the main character get the exact same types of Pokemon over and over again, teaching them moves like Aqua Jet, Flamethrower, and junk that his reserves already know at Oak's lab and they do it better. This is why I feel Pokemon like Quilava and Torkoal are wasted on Ash. He has Charizard and Infernape. Why pick one of them over these two fire powerhouses? Also Ash does not need to bond with every single Legendary Pokemon. Seriously give the other characters on the main cast a turn.
And to be honest it wasn't BW that made me lose interest in Ash, it was DP, my favorite saga so far. Even then I realized Ash was doing the same thing over and over again. The truth of the matter is Pokemon is repetitive no matter how you look at it. The games main plot is to get badges and win the league, while stopping a new evil team all the time. Me personally, I feel Ash peaked a long time ago and the writers just use him as a safe lifeline so don't have drop in ratings like Yugioh and Digimon, but while they avoided this problem they have created another one and ratings are dropping anyway. The truth of the matter is, I probably would like Ash more if he simply moved to a full on
mentorship role for a new character. Not like Brock, I would actually make him a very important part of the show, but as main character goes, what more does Ash have to learn? He's just learning stuff he's already learned before. And that is my personal take on this. Feel free to hate it.