These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Alternate Character Interpretation: Is Amy really in love with Sonic, or is she trying to hook up with him just so she can be famous too? She always acts like an obsessive fangirl when she's around him, and even he finds it annoying. Plus, Sonic being a hero means he's famous or will be famous someday, and maybe Amy wants to be with him just because then she can claim to be "the legendary Sonic the Hedgehog's girlfriend!"
Archive Panic: Nearly seventy games in twenty years, several animated TV shows, countless cameos in other series, and several comic series, one of which has been around since Sonic's heydey, and is still going to this day.
Shadow the Hedgehog. The amount of those who consider him at least one of the best things in the series are equal to those who consider him the worst. He was actually quite popular atfirst, but his characterization and unorthodox gameplay from his titular game left many bitter towards him.
Tails. While he is a popular character, he does have his fair share of haters, notably players that didn't like him for how he played in Sonic 2.
Shadow is occasionally criticized as such; he's overpowered in nearly every case except his own game because of the gun usage.
Silver also received such criticisms for his psychic powers and the ability to use Chaos Control like Shadow. To the point where when he was trying to kill Sonic, he came VERY damn close to succeeding.
Complaining about Shows You Don't Watch: The fanbase is very quick to start ranting and raving about how any new game will "ruin Sonic forever", often months or years prior to the entry's release. Let's not even get into the squabbling that occurs after a game is released.
Designated Protagonist Syndrome: A few accuse Sonic of having little personality and backstory compared to the rest of the cast. Of course, despite those claims he still tops in almost all popularity polls through the years.
Dork Age: No one can seem to decide on exactly when it started and when it ended, but the vast majority considers at the very least the year of 2006 to have been part of it.
8.8: Fans flipped out at Unleashed's atrocious scores in the press (in a few cases, worse than the universally-panned Sonic '06), many of which blamed the Werehog for ruining the game entirely.
Fang the Sniper known as Nack the Weasel in the U.S. a recurring character in the Sonic franchise between the years of 1994 and 1998 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.
For that matter Mighty the Armadillo and Ray the Squirrel also got to appear on posters in Sonic Generations and are popular thanks to the Archie comics even though they only appear in the games (SegaSonic the Hedgehog and Knuckles Chaotix).
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-nonsenseninja and the Only Sane Man of the trio.
Though they are controversial characters among the fanbase due to appearing in the imfamous Sonic 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 do to the Archie comics featuring his as a major character. Mephiles who while his plans are so ridiculously complex that they should not work, fans actually consider him a pretty cool villain. This could be attributed to actually killing Sonic.
Tiara has her fair share of fame despite never being properly released. Tiara's game (Sonic X-Treme) was infamously canceled.
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 Breaker status) with Cosmo and Bunnie Rabbot also worth special mentioning.
Fandom Berserk Button: Numerous examples in the series. Common mistakes that get ire from Sonic fans include:
Calling Shadow's Super Form "Hyper Shadow", a mistake stemming from Prima's Sonic Adventure 2 game guide. This one is a surefire way to light the fuse to a Flame War.
Likewise, referring to Super Knuckles as the less distinguishable Hyper Knuckles, something that originates from the Archie comics.
Mention any of the old backstory used in English speaking countries prior to Sonic Adventure (i.e. Mobius, Sonic's speed coming from his sneakers) and you'll likely be blasted by a group of "Only the Japanese stuff counts" purists. Which will then trigger a war with the "It's our childhood memories and we don't care if it's not really canon" fans.
Not to mention confusing the Archie, Fleetway, or cartoon continuities with the canon of the games.
Debating whether Ivo's real name is "Robotnik" or "Eggman" is another classic flame war kickstarter. Sega settled the issuenote both names are official; Robotnik is his real name, while "Eggman" is the nickname that everyone uses instead, but even this works as well as Shigeru Miyamoto's word on Shiek's gender.
Fandom Rivalry: Sonic and Mario were this from the 90's and early 2000's; one of the most classic examples in gaming history. However, fans of both series from that era seem to laugh about the rivalry nowadays and have evolved to become amicable with each other. Newer fans who didn't grow up during that era tend to overlap.
Sonic fans and My Little Pony: Friendship Is Magic fans are notorious for clashing with each other, which happens a lot on each other's fansites. This is mainly because the two fandoms are Not So Different, but absolutely hate that fact being brought up. It got so bad that for a while, the famous brony website Equestria Daily explicitly banned any Sonic related content from being posted on it.
Friendly Fandoms: As noted above, the Sonic fandom has ironically become one with the Mario fandom. They're also quite friendly with the Mega Man fandom and people who like one series tends to like the other.
Fan Dumb / Fan Wank: A prime example. There was even an article in Wired magazine about it.
Franchise Original Sin: The Cliche of Sonic (or sometimes his friends) using the Chaos Emeralds exclusively as an Eleventh Hour power up, as well as the cliche of Eggman being upstaged by a Monster of the Week that goes out of his control, that started around the time Sonic Adventure was released and was prominently overused in many of the Sonic games since. The recent games have been rectifying this by demoting the Emeralds back to bonus power-ups like before, and making Eggman a more prominent villain again.
Game Breaker: Cream in Sonic Advance 2. Makes the bosses a LOT easier. She's a game breaker again in Sonic Chronicles, where she can provide all but unlimited special move use for everyonenote especially if you give her Ferox, which makes Action Commands automatically succeed, or better yet, actually master her Action Commands so that you can pull them off reliably. She also breaks the game in Sonic Battle, where all of her moves are good or decent at worst. That's saying something. Her slightly below average stats don't change this either.
Also the combination of Knuckles with Tails as your partner in Sonic Advance 3 made most levels a joke, considering their combined aerial abilities.
In Sonic Adventure 2: Battle, there is Amy, Chaos, and Tails' alternate costume for the racing, treasure hunting, and shooting modes respectivley.
Amy: She may be slow and can't jump high, but she gets her specials every 10 rings rather than 20. Its not uncommon for her to continuously kill you and freeze you into submission.
Chaos: He's also slow, but he can breathe underwater and his third special freezes the opponent for a whopping 30 seconds!
Alt Costume Tails: No specials, but he moves at speeds that would make Sonic blush!
Goddamned Bats: Nearly every single enemy in the second half of Sonic Chronicles can act as this due to either ridiculous defenses, regenerating health, poisoning you every chance they get, leeching off your health, or any combination of the previously mentioned.
The Raptor Hawks in the first half of the game probably count, too. Although there's only six of them at the most, they have 120HP, do ~50 damage per hit, and can use "Evading" whenever they want. It's a good thing when they use their Special move, Feather Barrage, because it's easy to counter.
The artificial chaos enemies from Sonic Adventure 2. Very impressive reach, very hard to kill, and start appearing in levels that are already difficult to begin with!
Guide Dang It: Act 2 of the Carnival Night Zone from Sonic 3 still haunts people to this day.
Hype Backlash: The series suffers a great deal from this. Ever since Sonic Heroes or all the way up to Sonic Colors, every new game that is announced is met with almost instant approval by fans once more info comes out, only for the game to be nowhere near as good as its hype would entail. The fallout from this is almost a never pretty sight as it leads to arguments about if the game was actually good or not.
Oddly, this isn't really the case, so much as it is a case of Neverlive It Down. The "green eyes" debate was caused by about five members of Sonic Retro during the time Sonic 4 was being hyped, who decided to complain about how the game was going to be horrible and nothing like the classics before going into a rage about Sonic having green eyes. Despite this only being a few select members, this sparked lots of hate towards the (Already infamous) Sonic fanbase, and had people all over the internet claiming that Sonic fans can't be pleased and will complain about anything. This has even become somewhat of a meme among the Sonic fanbase.
Just Here for Godzilla: Most fans play the 3D games for the Sonic gameplay rather than for the many, many other gameplay styles, even when it can comprise as little as 1/4th the length of the entire game. This has resulted in Sonic being the only playable character in most of the more recent games.
Many people played the Adventure titles solely for the Chao Gardens. Curiously, this feature was removed from later games despite their popularity.
My Real Daddy: In terms of voice actors, Mike Pollock seems to be becoming this for Robotnik; he's played the character more than anyone else and is the current official voice for nearly every work of Sonic fiction. Not to mention most of Robotnik's other voice actors are either uninterested (Jim Cummings, Gary Chalk) or dead (Long John Baldry, Deem Bristow).
In terms of the development of the games, the series was created by 3 people: Yuji Naka, the founder and former head of Sonic Team, as well as the programmer of the Genesis platforers, Naoto Oshima, the actual creator and designer of both Sonic and Eggman, and Hirokazu Yasuhara, the designer of the first games levels (including the famous Green Hill Zone). Yuji Naka took most of the credit for creating the series, similar to Kenji Inafune's involvement with Mega Man. Sadly, all 3 of them no longer work with Sega, and the series is currently headed by Takashi Iizuka.
Narm Charm: The corny dubs of most of the games may be annoying, but the thrill of the gameplay is usually worth it.
Never Live It Down: Games like Sonic 06 and Shadow The Hedgehog are black marks on the franchise that no one will let Sega live down, regardless of how many good games there are. On a larger scale, the series and fandom will likely never escape the Broken BaseFan Dumb and Hate Dumb that plague it to this day or the reputation gained from said Fan Dumb.
Older Than They Think: A good number of fans seem to think that Amy has only been around since the Sonic Adventure days/is a recent addition. She has actually been around for about or (at least) almost as long as Tails (depending on whether you count the manga or Sonic CD as her debut).
Vector was created around Sonic 1 development, and Charmy is from the same manga Amy made her debut.
When Silver got a starring role in the Milestone CelebrationSonic '06 with Sonic and Shadow, fans felt he was usurping worthier characters like Tails or Knuckles and accused Sega of being biased against their non-hedgehog characters. His cameo in Brawl also led to claims of this.
Silver being That One Boss supreme in the game didn't help matters, either.
The Rivals games were more enjoyable before we found out Nega kicked Eggman out of the villain spotlight.
Sonic the Hedgehog (2006) managed to make Shadow the Hedgehog more bearable for some of his previous haters. Since the previous game saw him reach the end of his Quest for Identity and resolve to put the past behind him, this game saw Shadow greatly cut down on the angsting and replace it with stoic badassery. And from a purely technical perspective, his gameplay is probably the least broken out of the three main heroes.
In Sonic Generations, even haters of Silver have admitted to loving his new, more powerful form and the boss battle against him. His appearances in the comic have also made him one of Sonic Archie's most popular new characters, to the point of him getting a new Sonic Special.
Ship Tease: The series isn't really about romance(No matter what the fans try to convince you otherwise) but that doesn't stop it from teasing potential pairings. At least all of the list couples above have been teased at some point.
Die for Our Ship: Let's just say the community isn't very kind to a third wheel in their potential pairing and leave it at that.
Ship-to-Ship Combat: Its Sonamy vs. Shadamy, Knouge vs. Shadouge, Silvaze vs. Sonaze, and Sonaze vs. Sonamy.
It's made all the more confusing because neither of them is particularly interested in romance (bar Sonic X and the comics), to the point where Tails outright hates romance in Adventures of Sonic the Hedgehog, and, to a lesser extent, the games.
So Bad, It's Good: Among the usual candidates named for this are multiple song lyrics, most strikingly We Can, My Sweet Passion, and the in-level Knuckles raps from Sonic Adventure 2, the campy dialogue during levels, and, to a lesser extent, in some cutscenes, and almost everything about Shadow the Hedgehog and Sonic the Hedgehog (2006).
Villain Decay: Reverse-proportional to Eggman's Character Development. As he becomes more and more humanized and sympathetic, he becomes less and less evil. Of course, Eggman has many fans precisely because of this morality shift, so perhaps it isn't all bad...
He's been getting more dangerous as of recent games. Interestingly this is done without compromising much of his clownish semi likeable personality from before.
What an Idiot: The Nocturnus tried to conquer the ancient world and they did conquer the Twilight Cage — and given the Cage's Year Inside, Hour Outside effect, Shade probably took part in both conquests. Why did she not expect Ix to actually want to conquer Earth?
This is even played up in one episode of the TV series — when a rival genius' shapeshifting robot defects, Dr. Robotnik boasts that he deliberately designed Scratch and Grounder to be idiots, so they'd never defect.
Shadow the Hedgehog was purposefully intended for older fans. It was originally going to have a T rating, but backlash for giving Shadow his own game and intentionally making a Darker and Edgier installment (despite fans requesting that Shadow get his own game since Sonic Adventure 2/Sonic Heroes and requesting for a Darker and Edgier installment for a while) led to SEGA/Sonic Team censoring it to fit for the E10 rating. This shift led to the final product being torn between which group of fans it was trying to appeal to, succeeding at neither.
The inclusion of E102 Gamma in Sonic Adventure, Tails' and Eggmans' mech sections in Sonic Adventure 2, and Shadow's weapon of choice in Shadow the Hedgehog were intended to appeal to a segment of Sonic fans who had apparently been demanding gunplay in Sonic titles. While Gamma and the Sonic Adventure 2 mech sections were average at best, the inclusion of guns in Shadow's game lead to the single biggest complaint people have about the title. Make of that what you will.
The Woobie: E-102 Gamma. First major character to be killed off, after a lifespan of one day, which unlike Shadow or Emerl, was not commemorated or recognized by the other heroes. He shares this with Chip.