Broken characters in fighting games

[dastrn]

SSBB: MetaKnight, Falco, GW, DDD, ROB, ICz, and Snake.
SSBM: Sheik, Fox, Marth, and Falco
SSB64: Pikachu and Kirby

You are just listing top/high tier. That's not how brokenness works.

Metaknight is Broken in Brawl. Falco, G&W, DDD, ROB, Ice Climbers (lol), and Snake are not even close.

No one was broken in Melee. There were legitimate arguments for all 4 of the characters you listed being the best. They were extremely well balanced.