Ideally, I'd want first party characters to be a mix of recent-yet-significant (Wii Fit Trainer, Miis, most Pokémon and Fire Emblem newcomers), rounding out parts of existing series (most Mario newcomers, putting Ridley and Chrom in Ultimate), and highlighting cult classics that aren't discussed anymore but have fans that pine for the games long after they've seemingly been left behind by Nintendo (Pit in Brawl).
For the first category, I'd like to see a Style Savvy / Girls Mode character. It's a fashion / business sim that is popular for its unusually high quality among the genre (fashion sims are usually low budget shovelware) and visual novel storytelling aspects. It's not discussed much online unless you know where to look, because it's aimed squarely at women and anyone else into feminine fashion, but it is nonetheless a great series that should be seen as a core part of Nintendo's identity. Then there's the Rhythm Heaven series, a game series that is genuinely loved by most people who play it, with great gameplay that doesn't just refer to Dance Dance Revolution like most other rhythm games do. The only problem continues to be that people can't agree on who the Rhythm Heaven character could be, but otherwise a newcomer from this series would go over well.
For the second category, we have some characters that are still demanded but are part of existing series that usually have a bunch of characters playable already. Notable among these are Dixie Kong, Toad / Captain Toad / Toadette, Bandana Waddle Dee, and any Pokémon or Fire Emblem character that is not part of the newest games on the market like Lugia or Zoroark or Caeda or Lyn. Of this category, I'd stress Dixie Kong's absence in particular, as it feels like a core part of the DK crew is still missing, but that's probably just my bias. A couple other examples are Krystal, Fiora, Elma, any Xenoblade character really, it's odd that it's a growing series yet so far Shulk remains the sole representative of it for now.
The last category is my favorite. It's where no one has to care about relevancy anymore, you only need to care about whether you feel the game the character comes from is as good as any of the other games currently represented in Smash. Chibi-Robo no longer relevant, their series dead in the water? Who cares, put him in the game because the Chibi-Robo games are genuinely great. You want retro picks like Takamaru and Balloon Fighter? Go ahead, no one's gonna argue with you that either game is bad or that their main characters wouldn't be fun in Smash. Remember how much fun Sin and Punishment was on the Nintendo 64 and Wii, since both were made by legendary shoot-em-up game developer Treasure? Let's get Saki Amamiya in there!
Those are the three approaches I wish the Smash series would take. I'm not interested in discussing how likely any of this is, I just want to use this as a springboard for the rest of us to get creative and open about our wants.
