Not exactly the most original thread idea, but oh well.
In: Gardevoir.
I briefly considered choosing Colette from Tales of Symphonia, but in the end, I wouldn't actually enjoy playing as her, and, most importantly, it would be just heart-wrenching to see her be beat up.
Not that I'd have no pity with Gardevoir, but that thing is a powerful Pokemon. It's used to it?
Out: Pacman.
There are two characters I can think of right now that I hate, but my hate for Tingle recently got weakened. I'd hate Waluigi, too, but I can't take him seriously enough in order to summon up the necessary energy.
So, Pacman.
A gaming icon, and nothing more.
You have the choice between either the traditional, old-school Pacman, who is just a yellow, round thing with a big mouth. Unlike 2d Game&Watch, that makes Pacman very limited. His inclusion like this would be cool for a moment and then just seem weird and forced.
The other possible form is 3d, has eyes, arms and legs, and a wife called Mrs. Pacman.
I can think of no other character whose inclusion would disgust me as much as this one.
The character design is just some of the worst that has ever existed and is but a symbol of how the industry tries to keep alive popular old themes in a suspended animation for the sole purpose of draining money from die-hard fans with mediocre products.
If this Pacman is in, I won't buy the game. Well, I will, but I'll personally send a letter to Sakurai explaining in detail how much he failed to keep up the good work.
Oh yeah.
AT: Elite Beat Agents.
I understand that some of you may have forgotten them for a moment, which explains why not everyone suggested them as the perfect AT. You don't have to be ashamed of that, it happens to all of us from time to time.