Having now put 70+ hours into Pokémon HeartGold, I'd like to think I'm in a decent position to give suggestions on how to improve the series. These aren't so much huge decisions that could change the mechanics of the game as a whole, as little niggly things that, 70 hours in, now infuriate me as I play HeartGold. If I had my way, I'd make all the following changes before Pokémon Black and White are released.
1) Let me turn off unnecessary animations
There are times when I want to catch a rare Pokémon so I'm spending time walking back and forth through tall grass. Eventually, I encounter a Pokémon. My chap stops walking, the screen flashes numerous times, dramatic music plays, there's an annoying animation of grass flying past, and after all this... it's a Rattata. I know there's an option to remove battle animations, and I already have that enabled, but I'd love another one that lets you skip straight to the two Pokémon facing each other, allowing me to just choose 'Run' and move on quickly. Speaking of which...
2) Less Rattata
Seriously. How many times does a Rattata turn up? They're everywhere, and I just run every time. They're worth almost no Exp and they're rubbish. Less Rattata, more varied weak Pokémon please. At least that way I can expand my Pokédex a bit quicker instead of going for 'Run' every time.
3) Less annoying evolution requirements
I can just about handle evolutions that require you to trade a Pokémon while it's holding an item. It seems a bit over-the-top but whatever. What really annoys me though is the Pokémon that can only evolve if they're happy. It would be annoying but fair enough if it was necessary for only one or two Pokémon, but as it is I've got a Golbat, Chansey, two Eevees, a shiny Pichu, a Togepi and a Budew all sitting in my box waiting to be cheered up.
4) Make the Battle Frontier more exciting
Every time I go to the Battle Frontier I get excited, then I remember that it's actually really disappointing. I wish you could use it to evolve your Pokémon, or at the very least I wish it would give you Battle Points a lot quicker so you don't spend an eternity playing just so you can afford a Razor Fang.
5) Let me choose where to put Pokémon I've caught
I'm a bit OCD so I have a habit of renaming my boxes and sorting them into different categories. My first box is called BEASTS and it's where all my super-strong and Legendary Pokémon go. The next couple of boxes are just general ones I've caught, Box 5 is called EVOLVE and it's where I put the Pokémon I still need to evolve, and Box 6 is where I store all the Unown and alternative Pokémon I've caught (shinies, spiky-eared Pichu, etc). I hate how, when I catch a Pokémon, the game automatically puts it in the box I was last looking at in the Poké Centre. I don't want to put Tauros in EVOLVE, so give me an option to put it somewhere else so I don't have to spend 15 minutes arranging everything later on.
6) Please stop asking me if I want to use an HM
I'm in a cave, and the room has loads of rocks in it. I go over to a rock and press A. "This rock looks like it can be broken! Would you like to use Rock Smash?" Yes. I then have to watch an animation where my trainer thrusts his Pokeball into the air, a Pokémon zips by and the rock breaks. I move on to the second rock. "This rock looks like it can be broken! Would you like to use Rock Smash?" This is really infuriating. If I'm standing in front of a waterfall and pressing A, of course I want to use Waterfall. If I'm in front of a rocky hill and pressing A, I obviously want to use Rock Climb. Why go through this rigmarole every time? If I enter a dark cave and I have a Pokemon with Flash, why not just light the cave?