Moving away from this, the idea of “Big 3” got me thinking, who are everyone’s “Big 3” not included at the moment, and why do you want those characters.
I think my most-wanted characters at this point (in no particular order) are Doomguy, Geno, and Dante.
Geno is 100% unabashed nostalgia. Super Mario RPG was one of the first video games that I played (I can't remember if it was THE first, but it was one of the first ones that I really got into, along with Kirby Super Star and Wario Land 2). Geno really stood out to me because of his design - for whatever reason, he reminded me a lot of Piccolo from Dragon Ball Z, who was and still is my favourite character in that show. Also, given the legal issues surrounding the character, a game like Smash Bros. is one of the few games where he even has a possibility of appearing. (the only other cases where he had a chance were games like Fortune Street or the handful of Square-Enix-made Mario sports titles, and he didn't show up in those)
I only got into Doom through the 2016 reboot, and I haven't played the original games yet, but that game was easily the most fun that I've had playing a single player first person shooter game. Doomguy, or the Doom Slayer if you want to make him sound serious, played a big part in that - for a character with no lines of dialogue where you only occasionally see his arms or legs, they managed to make him so entertaining through his actions alone. I'd love to see the developers of Smash translate that game's frantic, run and gun, "stopping means death" style of gameplay into Smash. I realize that his chances aren't likely (Japan tends to frown upon games with large amounts of gore), but Doom's a hugely influential series (it may not have created first person shooters, but it certainly popularized them)
As for Dante, I played through the Devil May Cry series a couple of years back, and before I had even started Devil May Cry 4, I could easily see him working in Smash. I wrote up an entire moveset for the character that, thanks to incorporating weapon switching, was more like three movesets, and I could easily make another one based on Devli May Cry 5 on its own. While I don't know how likely he is for two very opposing reasons (on one hand, four Capcom characters might seem excessive - on the other hand, Capcom has a ton of characters to choose from, with pretty strong competition from a Monster Hunter, Phoenix Wright, Jill Valentine, or Leon Kennedy), I'd love to see what they could do with him, especially if they base his moves on Devil May Cry 3, 4, or 5. (DMC1 could work, though it would be more basic than the others, and I don't recall anything interesting about DMC2's combat)
Around Smash 4's launch, I think it was
![King K. Rool :ultkrool: :ultkrool:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
![Ridley :ultridley: :ultridley:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
![Bayonetta :ultbayonetta: :ultbayonetta:](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
(not counting Snake's return, or characters that I saw as being impossible like Banjo and Kazooie), but Smash Ultimate (and Smash 4's DLC) has been very good to me in that regard.