This is really simple honestly, who do you main in any of the super smash bros games, from Nintendo 64-Smash 4 for 3DS/Wii U, one per game or just one whole main.
My mains are:
Super Smash Bros 64: Kirby
Super Smash Bros Melee: Roy/ Marth
Super Smash Bros Brawl: Toon Link/ Link
Super Smash Bros Wii U/3DS: Shulk/ Kirby
Kirby was just such a lovable character and he can jump multiple times in 64 and he wasn’t nerfed like in melee. Marth and Roy basically same characters except Roy is beefier, it’s really easy to use them aswell, Toon Link and Link are both easy concepts and since toon link is tiny he has a smaller hit box and could run faster. Shulk just randomly became a main and he has huge range that I love, and as for Kirby in Sm4sh, well he was beefed up and I love it, so much potential is put into him