Here's what I like to see.
Eliminate the anti-Dowsing Machine rule of certain places, such as Hotel Richissime where having to find lost items with it in place might be counter-intuitive as the areas you need to search get bigger.
Ban the following moves from the opposing roster of Pokemon in the restaurant battles as they would might make the battles drag on one turn too long:
The rivals being less of or even not being pale imitators.
Make the Gym Leaders more proniment.
Better Post-Game Content.
Toning down the Uncanny Valley or even removing it.
A better post game.
Everything new from X & Y being made easier to follow.
Letting Pokemon like Chatot and Hawlucha participate in air battles.
: "I think instead of banning weak pokemon from Wonder Trade, we can have a tier list. From crap to legendary. So you can get stuff that's on-par with your pokemon."
said "Have all the Legendary Birds Roam Kalos. If not, have the Legendary Dogs, the Eon Pair, The Lake Trio, the Musketeer Quartet, or the Kami Trio roam Kalos instead.
Have one of the Legendary Golems appear inside the Cave of Emptiness.
Be able to activate Lysandre and Xerneas'/Yveltal's battle music during matches in the Battle Maison.
Return of swarms in each area of the whole Kalos region.
The VS Seeker/Pokegear/Pokenav/any other trainer rematch thingy.
Gym leaders, Elite 4, and Champions from other regions visiting the Battle Chateau.
Workers actually filling up the hole in Geosenge Town after you beat the game. I get irrationally uncomfortable everytime I see it.
A way to catch Lugia/Ho-oh/Dialga/Palkia/Giratina in-game. (I didn't request for Kyogre, Groudon, and Rayquaza since I'm still looking forward to Hoenn remakes.)
Wi-fi events for Mew/Celebi/Jirachi/Deoxys/Manaphy/Darkrai/Shaymin/Arceus/Victini/Keldeo/Meloetta/Genesect."
Toning down the annoying-ness of Emolga.
Tuning down the narmy-ness of the Ultimate Weapon scene.
The option of adjusting the difficulty during the game.
No hordes of wild Pokemon that get annoying.
Toning down the difficulty of Magnezone & Magneton in the Super Training.
No game-breaking bugs.
Have the mechanics in Lumiose City disappear after you free the power plant.
Bring back rematches.
Have Zygarde as the mascot.
: "Well, for the story I want it to be darker toned. The Gym Leaders should
be more prominent in the story.
In Pokemon Z, the player should travel in an alternate Kalos where everything is not so beautiful.
This sounds like Majora's Mask territory, doesn't it?
But it would be cool if they done something like this.
And more Mega Evolutions like Mega Raichu would sweet!