Not counting echoes to keep it simple. The only character I really cared about that became an echo was Dark Samus.
SSS Tier:
My top two requests for literal decades. Calling them my dream characters is an understatement. Gotta love Rare. They even share the same trailer format, and their trailers feel so much more like "welcome home" trailers, making them feel really unique and heartwarming. Friendly reminder that neither character had been in a game from their series in over a decade at the time of their reveals.
S Tier:
I hopped on the Ridley bandwagon in Smash 4, only for that to get shot down hard by a deconfirmation. Still never played any Metroid games, but Ridley came to be my most-wanted aside from the two above. When Ultimate was revealed at E3 last year, "everyone is here" was an incredible way to start it, but of course everyone's attention would be on newcomers. And what a statement Ridley was - Ridley's confirmation really opened the door for so many other characters - for the first time ever, fan favorites like K. Rool, Banjo, Geno (rip), and Isaac (rip) felt like actual possibilities instead of just pipe dreams.
A Tier:
I'm no Persona fan, but the manner in which Joker was revealed was particularly hype; it wasn't a Smash event, so seeing that Smash invitation (less than an hour before the game launched, mind you) was an absolute and completely literal jaw-dropper. As for Inkling, their reveal was bundled with Smash Ultimate itself so they get a bonus from that, they were almost a mandatory inclusion in a new Smash game anyway given Splatoon's success.
B Tier:
Simon was a hype reveal, making we wish I'd played Castlevania. The middle two are great characters, but were undermined by Grinch hoax and being in the final Direct before the game came out. And Hero we all expected, and I have no attachment to Dragon Quest. And for about half an hour, they were the personification of all the week's prior Banjo rumors being false -- thankfully, I waited until the end instead of complaining online, and the Banjo payoff was glorious.
C Tier:
Don't get me wrong, Isabelle is a fine character. But her reveal was incredibly underwhelming for me, since I've never been a big AC fan, and it was hot off the heels of the K. Rool reveal. Plus she's the least unique non-echo newcomer, being partially based off of Villager.
The reaction to the Final Smash Direct is just the result of the fans overhyping themselves after the first four newcomers: Inkling, Ridley, Simon Belmont, and King K. Rool. It would be a heruculean task to follow up those along with every veteran. There’s nothing wrong with Isabelle or Incineroar, they just weren’t “hype enough” for final reveals. People who took the deconfirmation wave as a face spit ignore all the other good will Sakurai earned with this game.
Let's not forget the Grinch hoax, too, which amplified that to an extreme. Incineroar and Piranha Plant are fine characters, but for people who were expecting Mach Rider,
Banjo-Kazooie,
Geno, Chorus Kids, Shadow, and
Isaac, it was definitely a letdown.