Ok, so I’m putting a lot of thought into a realistic wishlist.
First of all, a new Mario character might be a given.
Paper Mario would be interesting, but also, Bowser Jr would be a safe choice. As far as final smashes are concerned, PM could use Supernova, and BJ could have Shadow Mario transformation.
While on the subject of Mario, King K Rool would make a good DK character. He is DK’s “Bowser”
We don’t really need any new Zelda characters, but someone please make a different final smash for Toon Link.
As for Samus, Dark Samus would be a good new character, hidden, of course.
Now, Kirby characters, we don’t need new ones, but that’s not gonna stop Sakurai.
For F-Zero, Black Shadow would be a good villain playable character. The game needs more villains. BS is Captain Falcon’s “Ganondorf”
As for Pokemon, replace Lucario with Zoroark
For Starfox, make Krystal a character. Also, give Falco an Arwing final smash. When it comes to Wolf, give him anything but a Landmaster.
Now, for Fire Emblem, bring back Roy with better attacks. Keep Ike, and add whoever is in whatever new game that comes out between now and the game’s release.
For Earthbound, keep the current characters, and actually give them moves they use in the game.
We need no new Kid Icarus characters.
As for other Nintendo characters, add Little Mac, Saki/Isa, and some other decent Nintendo characters.
Now, for 3rd party, keep Snake. Get rid of Sonic. MegaMan is a good pick. Simon Belmont is another good pick. But what I feel like what would be one of the best 3rd party options is Ryu Hayabusa.