- Shadow the Hedgehog, Blaze the Cat and Metal Sonic are probably the most stand out examples among the fanbase.
- Shadow quickly took the spot as Sonic's rival after Knuckles became much friendlier to Sonic, and his first appearance in Sonic Adventure 2 was essentially his high point, especially due to his Heroic Sacrifice. Heck, he was so popular that they brought him back in Sonic Heroes and gave him his own game. Opinions about him afterward vary for lack of a better term and easily may be the most controversial character in the whole franchise.
- Blaze's powers and appearance as a Defrosting Ice Queen with Character Development won her several fans, which only increased as she proved to be badass enough to fight Sonic on even footing during her debut game series and gaining her own Super Mode, something no other female character can lay claim to. The fact that said games are considered to be fairly good titles only improves her standing, and her lack of screentime outside these titles and the odd spinoff make her one of the most popular of Sonic's friends in the modern era.
- Metal Sonic is especially notable, because aside from Sonic CD, the character made no appearances in the major classic games,note being delegated to more obscure titles like Sonic Triple Trouble, Sonic the Fighters, Knuckles Chaotix and Sonic R, and mere cameos or non-canon appearances in the Sonic Adventure series. After his surprise comeback in Sonic Heroes, he was permanently cemented as a significant recurring foe in the series.
- Fang the Sniper (known as Nack the Weasel in the U.S.) was a recurring character in the Sonic franchise between the years of 1994 and 1998 and has many fans who want him to make an appearance in anything. Some of these fans got their wish when he cameoed on a wanted poster in Sonic Generations.
- All of the Chaotix are this, especially after Sonic Heroes revamped them into a trio of screwball, Crazy Awesome detectives. Espio especially. After all, he is a no-nonsense ninja and the Only Sane Man of the trio.
- Though they are controversial characters among the fanbase due to debuting in the infamous Sonic the Hedgehog (2006), Silver the Hedgehog and Mephiles the Dark have their share of fans. Silver, after his boss fight in Sonic Generations proved to be actually fun and also due to the Archie comics featuring him as a major character. Mephiles who, while his plans are so ridiculously complex that they should not work, is actually considered a pretty cool villain. This could be attributed to actually killing Sonic.
- E-123 Omega, especially when he became an Expy of HK-47 (see below).
- There's also Jet the Hawk and the Babylon Rogues who have a sizable fanbase.
- E-102 Gamma, extraordinaire, is notable as a character that is almost universally liked by fans. His Heroic Sacrifice (which stuck, not counting E-102r "Chaos" Gamma in Battle), his surprising amount of Character Development given his screentime, and the nature of his existence in general most likely helped.
- Tikal and Shade, the female echidnas who each have a pretty big fanbase considering how little they've been in the games. Tikal, unusually for an Exposition Fairy is rarely disliked by players. It helps that as a glowing orb in her spirit form, she only activates when you touch her, making it easier to spot so you're free to ignore her advice. She's a mysterious, sweet girl with a tragic backstory who has a less is more approach to her character, a beautiful theme, and is implied to be manipulating the protagonists to get them to confront Chaos. The fact that she's an ancestor of Knuckles certainly doesn't hurt either. Tikal actually managed to defeat Dr. Eggman in Sonic Wiki's Character Tournament.
- Orbot (aka "Ergo") from Sonic Unleashed. His Scratch and Grounder-esque dynamic with Cubot in Colors further cements this.
- Cream the Rabbit while somewhat controversial as a Moe character that dislikes fighting and is very Japanese in comparison with the rest of the cast, acquired a reputation as a Memetic Badass, thanks to being a Game Breaker in nearly all of her appearances. It helps that the shrillness of her voice was toned down after the first cast turnover, making her easier to appreciate.
- In another corner of the fandom, a great deal of prominence has been given to Honey the Cat, an extraordinarily detailed character who was Dummied Out of Sonic the Fighters. This may have motivated Sega's decision to promote her to playable in the 2012 'Xbox Live Arcade & Play Station Network Updated Re-release.
- Tiara has her fair share of fame despite never being properly released. Tiara's game (Sonic X-Treme) was infamously canceled.
- Merlina, the Big Bad of Sonic and the Black Knight has an impressive following despite her minimal time on screen. Attractive, cunning and one of the very few anti-villains in the franchise gets her a lot of love. She's also got kickass battle music, even compared with the series' standard for final bosses.
- In addition you'll often find a strong fanbase of particular alternate media characters, many of which urging for them to appear in the games canon. Princess Sally Acorn has perhaps one of the most notable fanbases even compared to some games characters (even if it extends to Base-Breaking Character status) with Cosmo and Bunnie Rabbot also worth special mentioning.
- Among the villains and bosses, Perfect Chaos has a large fandom due to being a titanic water god of destruction with an awesome design and roar and a wooby backstory. Dark Gaia as well, though not to the same extent. The Egg Viper, final boss of Sonic's story in Adventure, is widely considered one of the best Eggman mechas in the franchise, along with Death Egg Robot and Big Arm.
Ensemble Darkhorse / Sonic the Hedgehog
Due to the series' having a tendency to introduce new characters every other game until the Unleashed era, Sonic the Hedgehog has many characters that can be considered Ensemble Darkhorse by different sorts of fans. While they may have even been main characters in their debut games, they quickly fall to the side, leaving them to acquire fanbases of their own.