Got bored and made a new roster...64 characters in total (no, the question block is not a character).
ROW 1: Mario, Luigi, Peach, (Captain) Toad, Rosalina, Bowser, Bowser Jr., Donkey Kong, Diddy, K. Rool
ROW 2: Link, Zelda, Impa, Ganondorf, Toon Link, Tingle, Yoshi, Kamek, Wario, Rhythm Girl
ROW 3: Samus, Ridley, Pit, Palutena, Kirby, Metaknight, Dedede, Fox, Wolf, Captain Falcon
ROW 4: Pikachu, Jigglypuff, Charizard, Serperior, Greninja, Lucario, Mew-Two, Olimar, Takamaru, Dog & Duck
ROW 5: Marth, Caeda, Ike, Robin, Ness, Porky, Little Mac, ExciteBiker, Ice Climbers, Andy
ROW 6: Villager, Chibi-Robo, Wii Fit Trainer, Shulk, Inkling, Sonic, Simon Belmont, Mega Man, Pac-Man, Mog & Chocobo
ROW 7: Mii Fighters, ROB, Game & Watch, Mini-Kangaroo
OTHER NOTES
Some absent characters are alternates, and their differences are available via customization for either them or the main character.
Dr. Mario: Alt. for Mario
Sheik: Alt. for Impa
Zero Suit Samus: Can be activated the old way, via Final Smash, but only optionally, and is also selectable by herself under regular Samus’s slot. Not an alternate costume/similar moveset thing.
Dark Pit: Alt. for Pit
Falco: Alt. for Fox
Lucina/Roy: Alts. for Marth
Lucas: Alt. for Ness
And of course, male/female alternates for Robin, Villager, WFT, and Inkling, as well as the Koopaling alternates for Bowser Jr.
Ganondorf, Toon Link, and Wolf are further “Luigi-fied”. Ganondorf now uses a few more magical attacks and some trident-based moves, but doesn’t lose the heavy, strongness he is now known for in Smash.
Toon Link’s Specials now make more use of different items, such as Fire/Ice Arrows, the Slingshot and the Deku Leaf.
Wolf uses explosives, laser rifles, and the Wolfen for his Final Smash. As a side-note, Fox’s new Final Smash also calls in the rest of Team StarFox in their Arwings to help him out.