When Super Smash Bros. for Nintendo 64 launched in 1999, no one could have predicted how influential the game would become. The main reason for this is the fighter selection. Getting to see Mario pummel Link was a Nintendo fan's dream come true. After the game released, series creator Masahiro Sakurai held a poll for Japanese readers to see which characters fans would want in a hypothetical Smash 2. Source Gaming translated the answers, giving a comprehensive view of who players wanted to see in a Smash Bros. sequel, which eventually became Melee.
The top most requested Mario characters were Bowser, Peach, and Wario. Bowser and Peach would become playable in Melee, and Wario made his debut in Brawl. Mewtwo was the top most requested Pokémon, and of course he debuted in Melee. For The Legend of Zelda, Ganondorf was ranked much higher than Zelda, Child Link (referring to Yong Link) and Sheik. These four characters made it into Melee.
Kirby's list of votes is particularly interesting. King Dedede was ranked the highest, but the second wasn't Meta Knight. Gooey, Kirby's friend from Kirby's Dreamland 2 and 3, had six more votes than Meta Knight. King Dedede and Meta Knight would later appear in Brawl, but Gooey would not. The Mother (Earthbound) series is also mentioned. None of the characters listed would become playable, but Jeff would become an Assist Trophy in Brawl, and Mr. Saturn would become a mainstay item starting in Melee.
For Star Fox, Falco ranked the highest, but Slippy actually outranked Wolf by a vote. Falco would become a series mainstay, and Wolf debuted in Brawl. Fire Emblem is also mentioned. It's important to remember that at this point in time, Fire Emblem was non-existent outside Japan. Marth was ranked the highest in this poll, and we know he debuts in Melee. Interestingly, part of the poll is dedicated to characters from Rare. James Bond actually outranked Banjo-Kazooie and Diddy Kong. Diddy would appear in Brawl. Bond likely will never be able to appear, but fans are still holding out hope for Banjo.
For those in the "aren't Nintendo group," Chocobo and Doraemon outranked Bomberman, Crash Bandicoot, Sonic, and Mega Man. This may sound especially surprising, but again, this poll was aimed at a Japanese audience. Doraemon is a big franchise in Japan. You also may be surprised that Sukapon outranked Pit. While Sukapon never made it as playable, he'll be appearing in Super Smash Bros. Ultimate as an Assist Trophy.
Overall, the highest ranking first party Nintendo characters were Bowser, Ganondorf, Mewtwo, and King Dedede. According to Source Gaming's translation, a few of these high-ranking characters were actually planned for Super Smash Bros. 64. This shows that Sakurai knew who fans wanted to see before creating the game. It is fascinating viewing a list like this today, seeing who a lot of fans wanted to see in the next Smash Bros. A lot of these came true, while others are still waiting for a shot in the spotlight.
The latest game in the series, Super Smash Bros. Ultimate, will launch on December 7th.