I've taken one character considered the absolute worst from each of the first three installments in the Super Smash Bros.
franchise and placed them on the list of options. They are:
Smash 64: Samus Melee: Pichu Brawl: Ivysaur
I would have put Kirby over Pichu for Melee, but Kirby actually has a few decent tournament placings (Triple R), while Pichu is only seen in competitive play when a top player is trolling (and the Pichu oftentimes still loses). Kirby also has better MUs overall.
I put Ivysaur over Ganon for Brawl because Ivysaur has worse matchups than Ganon and a worse recovery. Additionally, it is believed that Ivysaur on its own actually loses
to Ganondorf, and is the only character with a disadvantage against him in the game. Competitively, Ivysaur is largely skipped over. It is outclassed in damage-racking by Squirtle and in getting KOs by Charizard, and its weakness to fire (a common attacking type, notably by Olimar, R.O.B., Captain Falcon, Mario, and Ike) almost nullified its above-average weight.
Skipped Smash 4 because the game is only about a third of a year old, but it's looking like Lucina and Mii Swordfighter are top picks for worst characters in the game.
So, which of these characters is the worst?