Smash Awesome Bros.
Wii Fit Trainer is my new main
Previous Mains (In order of prescedence)
SSB: Kirby
SSBM: Peach, Ganon, Dr. Mario, Zelda, Fox, Falco, Kirby, Jigglypuff, Cpt. Falcon, Roy, Young Link, Pichu
SSBB: Zelda
SSBB(project M): Zelda, Ganon, Sonic, Peach, Mario, Snake, Lucario, Lucas
SSBU: Wii Fit Trainer, probably Villager

oh and here is your link
http://www.destructoid.com/japanese-artists-think-wii-fit-trainer-is-smokin--256606.phtml

previous mains
SSB: Fox, Kirby
SSB PC: Megaman, Sonic, Kirby, Pikachu
SSBM: Kirby, Fox, Captain Falcon, Jigglypuff,
SSBB: Pit, Fox, Kirby, Mr.Game and Watch, Lucario, Falco
SSb on Wii U: Don't know yet