Ensemble Darkhorse / Mega Man

    Mega Man Classic 
  • Many Robot Masters from the NES era still have a solid fan base, including but not limited to: Metal Man (due to his design and overblown weapon), Shadow Man (design and difficulty), Skull Man and Pharaoh Man (both looking badass), and Sheep Man, originally The Scrappy when Mega Man 10 was announced, but ultimately became this when the game came out.
  • And of course, there's the original Proto Man, who gets cool points for being Mega Man's brother, a rare robot that's neither allied with Light or Wily, and having a pretty great design and memorable theme, even if his actual boss fights as Breakman are pathetically easy. He's made playable in the 9, 10, and Powered Up.
  • Roll, Mega Man's little sister, has a fanbase of her own, even if not to the extent of Protoman's. She's adorable, a kindhearted Nice Girl, helpful in her few prominent appearances, has a crush on Mega Man (only in Powered Up, thankfully), and received a very pleasing redesign in Mega Man 8, one of the few things to carry over into the ninth game. While she was little more than a background prop in the NES games, the seventh installment gave her some speaking lines, the eighth upgraded her to shopkeeper, Powered Up made her a playable character with a goofy and fun playstyle, and has a surprisingly sad cutscene in the tenth game. She's become a Fountain of Expies for the female sidekicks later down the series who have all become popular themselves who share some aspect of her design and personality, including Iris, Ciel, Casket, and her Exe incarnation. Becoming a Lethal Joke Character in multiple fighting games earned her some attention as well. She even got her own series of character mods in the classic games!
  • Splash Woman (from Mega Man 9), who has a huge fan base and has made many players robosexual. Aside from Roll, she's one of the very few female characters in the series, let alone for the Classic timeline.
  • Enker, Punk, and Ballade, or the Rockman Killers, a group of Robot Masters created for the sole purpose of offing the Blue Bomber. Making their debut in the Game Boy titles (Rockman World in Japan), they subsequently reappeared in Mega Man V for one final battle with Mega Man (alongside Quint)... and then resurfaced years later in 10 as DLC Bonus Bosses. You can also obtain their weapons.
  • Also from Mega Man V, Sunstar, for his cool design and acting as the final boss in a series whose only final boss tends to be Dr. Wily.
  • Tango the robot cat only plays a major role in the Game Boy Mega Man V and makes a few minor cameos elsewhere, but his adorable design and general usefulness earned him many fans.
  • Bass is popular in some circles, although his largest fanbase is still his .EXE incarnation, which fans literally seek out ways to play as him or use a soul of his more than any other character despite his lack of availability, barring one game, and consider him to be the undisputed strongest character in the Battle Network games, barring certain events.

    Mega Man X Series 

    Mega Man Zero Series 
  • Harpuia became a huge Ensemble Darkhorse during the run of the Mega Man Zero series because he was likable Anti-Villain that ultimately showed himself to be a Hero Antagonist and later full blown hero
  • The Zero series spawned a few minor/temporary ones, like Chilldre Inarabitta and Leviathon.
  • Omega. This Ax-Crazy psychopath was popular enough that he came back as a bonus boss in ZX. Of course, he's Zero, so this shouldn't come as any surprise.

    Mega Man ZX Series 

    Mega Man Legends Series 

    Mega Man Battle Network / Star Force Series 
  • Colonel.EXE, Protoman.EXE, Tomahawkman.EXE, Searchman.EXE, and Bass.EXE—freaking INCREDIBLY popular from the Mega Man Battle Network game/Mega Man NT Warrior anime-manga series.
  • Sonia Strumm/Sky is this for western fans due to being one of the most likable and sweet characters of the cast and being actually capable of fighting semi-evenly with Mega Man. She's also, like Tron, pretty cute.
  • A.C. Eos is fairly popular as well for being both very relaxed and likable, and being fairly complex as the game later shows.
  • Hyde became somewhat subject to this to those who watched the Tribe season of the Mega Man Star Force anime, as he was changed from a sycophant quasi-Dragon in the game to an out-there, comic relief artist in the anime. It didn't hurt that his crowning moment of villainy was kidnapping the hero's mother and throwing her off buildings and bridges Green Goblin-style just for the lulz.
http://tvtropes.org/pmwiki/pmwiki.php/EnsembleDarkhorse/MegaMan