PLEASE DON'T POST YOUR OWN IDEAS. EVEN THOUGH MOST OF YOU WILL, I WANT THIS THREAD TO BE ABOUT MY THOUGHTS BELOW.
1.) The Nerfing of Stealth Rock. It's so common in most movepools and so easy to setup yet it completely neuteres Fire/Flying types, Bug/Flying types, etc.
2.) More moves that raise Attack 2 stages. Swords Dance is not enough. (inb4 Acupressure)
3.) Better Physical Electric and Ghost type moves. I actually cried a little when Shadow Ball was made special and the best move my Banette could use was Shadow Claw. Also dislike that Volt Tackle is exclusive to Pichu and its evolutionary forms but most other are limited to Spark/Thunder Fang. Luxray ;__;
4.) An ability that lowers the opponent's Special Attack. Intimidiate is very useful, especially on Bulky Pokemon like Gyarados. Why not a special variant?
5.) The Buffing of elemental Held Items. Items like Charcoal, Mystic Water, Miracle Seed, Magnet, etc. are pretty useless when taking into account Choice Band/Specs/Life Orb.
6.) The Nerfing of Outrage. Like one member of this forum has said in the past, it's broken.
7.) Less HM's. 1/3 of the members in my initial party in Diamond and Platinum were HM slaves. It made me rather unhappy.
8.) The Return of Diving. I loved it in Ruby and Sapphire.
9.) The Return of Exterior Bases. See above. The Villa in Platinum was a nice touch but I would love the choice of where I can put it.
10.) Less Zubat and Geodude in caves. A pet peeve really but it's getting old.
Pixel Art can be fun.