Use: Link, Zelda, Sheik, Ganondorf, Toon Link, Samus, Ike, Robin, Little Mac, Greninja, Wii Fit Trainer, Dark Pit, Shulk.
I would consider Link, Toon Link, Ike, and Dark Pit to be my mains. But if I had to limit it to my go to one, I would say Ike.
Don't use: Mario, Luigi, Peach, Bowser, Yoshi, Rosalina and Luma, Bowser Jr., Wario, Mr. Game and Watch, Donkey Kong, Diddy Kong, Zero Suit Samus, Pit, Palutena, Marth, Kirby, King Dedede, Meta Knight, Fox, Falco, Pikachu, Charizard, Lucario, Jigglypuff, Duck Hunt, R.O.B., Ness, Captain Falcon, Villager, Olimar, Dr. Mario, Lucina, Pac Man, Megaman, Sonic.
I can't get the hang of Rosalina and Luma, Palutena (I'm okay with Palutena), Duck Hunt, Ness, and Villager. I can't figure out how to use them and use them in a good way. The rest I'm just flat out not good at, or don't like.