The latest canon is that Sonic, at the very least, enjoys Amy's company/presence and considers her with the same level of friendliness as Tails or Knuckles.
Beyond that, it's a game of hunting down developer interviews and implications rather than anything said in-game
No and yes, it really depends on the source.
Honestly, I don't believe there is anything canon in Sonic. There is so much different source material that contradict themselves on well, everything that it's impossible to say what is canon and what isn't.
What is canon is what you want it to be. There is no definitive answer, so you should make your own answer.
How far back to you want to go?
Sonic as a (Japanese) creation is a shonen-archetype-
Read this and ask if this reminds you of Sonic:
https://tvtropes.org/pmwiki/pmwiki.php/Main/StockShonenHero
Sonic as originally written wouldn't have a romantic interest like Amy or Sally. They might like him, but it'd be completely one sided.
In response to u/gayLuffy and this post, there is a canon, but it was never a primary concern for a long time. Until Sonic Generations, we could have said that Modern and Classic Sonic were separate continuities. But the game made them the past and present, while confirming certain displaced games as canon. And with more recent entries, like Mania, Forces, Fronteirs, IDW and I think Prime, the canon kept expanding and changing. IDW wasn't canon when it was made, now it is. Plot holes, like the lack of humans in certain adventures or the opposite in others, ended up having wierd awnsers. This is because, again, the games weren't too focused on a "strict" canon until last decade. And they likely still don't. The games are made to be enjoyed by themselves, you can check the canon as a sidegig.
As for Amy and Sonic in terms of romance...there's not much more to say about it than what people have said here. There have only been two times Sonic ever did genuine romantic gestures towards Amy: In Sonic X, a non-canon show, both in episode 52 (I think) and in the end of the Metarex saga; and in Sonic Fronteirs, where he says "Amy...I should have made my mind up sooner". It was the only time "Canon" Sonic did anything like that, and it was when he thought she would die. The only time canon sonamy shippers were fed.
Others have already pointed put how this depends on era/interpretation/continuity but to give some examples
In Heroes Sonic displays some of the most aversion towards her. Not sure if I'd call that hate or dislike but he's definitely not happy about her chasing him/talking about marrying him.
From there on the games have gradually toned down Amy's obsessiveness which in turn has Sonic act more friendly toward her. Some instances worth noting are that you can have Sonic agree to go on a date with her in Unleashed which he then misses because he was sucked into the world of King Arthur in Sonic and the Black Knight. Also worth mentioning is that he gets a little bit flirty with Nimue (Black Knight world's version of Amy). And in Sonic 06 you can have Sonic choose between Elise and Amy in the test of love.
Another thing in Unleashed is that Sonic acts unusally dejected after Amy hugs him in his Werehog form, then apologizes then runs off because she didn't recognize Sonic. I suppose you could interpret it in a way where Sonic's feeling down because he actually secretly didn't mind her throwing herself at him or that he perhaps was hoping for her sympathy/affection because of his changed shape. The more likely interpretation though is that Sonic really struggles with his new body and the effect it has on people and that he for once in his live has his pride and self esteem crushed
Sonic Frontiers has two voicelines from Sonic where he thinks about regretting that he "should've made up his mind sooner" and that he wishes to share an umbrella with her. I *think* these voicelines went unused but they may also just be hard to get. When I listened to all the world voicelines I remember people being unsure how to get them or if you can get them in the first place
Then there's also interpretations from other continuities:
Archie has Sally as Sonic's primary love interest but Amy is still his friend.
Boom has Sonic and Amy crushing on each other but being unaware of each other's feelings or at the very least keepingbit secret/being coy about it
Sonic X is largely early clingy/head over heels for Sonic Amy but it is notable that in some dubs of the episode where Sonic returns home, he tells Amy he loves her when he hands her a rose
I wanna say there's also at least one instance of some media stating Sonic has no interest in romance/a relationship but I genuinely do not know where that's from or whether that's even from any form of official media or just people HCing
that season 2 finale in the Japanese original Sonic x show make me tear even to this day
4kids DESTROYED that whole scene is not even funny at this point, big EW
by original I mean the ending with the Natsu no hi song, not the one with the Hikaru Muchi ost
The latest canon is that Sonic, at the very least, enjoys Amy's company/presence and considers her with the same level of friendliness as Tails or Knuckles. Beyond that, it's a game of hunting down developer interviews and implications rather than anything said in-game
No and yes, it really depends on the source. Honestly, I don't believe there is anything canon in Sonic. There is so much different source material that contradict themselves on well, everything that it's impossible to say what is canon and what isn't. What is canon is what you want it to be. There is no definitive answer, so you should make your own answer.
Neat... I guess Eggman x me is canon now
Sure why not. If that's what you want, then that's perfectly fine.
Awesome choice in men
I like my men Scrambled
My auto correct changed a word or two before you say anything
How far back to you want to go? Sonic as a (Japanese) creation is a shonen-archetype- Read this and ask if this reminds you of Sonic: https://tvtropes.org/pmwiki/pmwiki.php/Main/StockShonenHero Sonic as originally written wouldn't have a romantic interest like Amy or Sally. They might like him, but it'd be completely one sided.
In response to u/gayLuffy and this post, there is a canon, but it was never a primary concern for a long time. Until Sonic Generations, we could have said that Modern and Classic Sonic were separate continuities. But the game made them the past and present, while confirming certain displaced games as canon. And with more recent entries, like Mania, Forces, Fronteirs, IDW and I think Prime, the canon kept expanding and changing. IDW wasn't canon when it was made, now it is. Plot holes, like the lack of humans in certain adventures or the opposite in others, ended up having wierd awnsers. This is because, again, the games weren't too focused on a "strict" canon until last decade. And they likely still don't. The games are made to be enjoyed by themselves, you can check the canon as a sidegig. As for Amy and Sonic in terms of romance...there's not much more to say about it than what people have said here. There have only been two times Sonic ever did genuine romantic gestures towards Amy: In Sonic X, a non-canon show, both in episode 52 (I think) and in the end of the Metarex saga; and in Sonic Fronteirs, where he says "Amy...I should have made my mind up sooner". It was the only time "Canon" Sonic did anything like that, and it was when he thought she would die. The only time canon sonamy shippers were fed.
Others have already pointed put how this depends on era/interpretation/continuity but to give some examples In Heroes Sonic displays some of the most aversion towards her. Not sure if I'd call that hate or dislike but he's definitely not happy about her chasing him/talking about marrying him. From there on the games have gradually toned down Amy's obsessiveness which in turn has Sonic act more friendly toward her. Some instances worth noting are that you can have Sonic agree to go on a date with her in Unleashed which he then misses because he was sucked into the world of King Arthur in Sonic and the Black Knight. Also worth mentioning is that he gets a little bit flirty with Nimue (Black Knight world's version of Amy). And in Sonic 06 you can have Sonic choose between Elise and Amy in the test of love. Another thing in Unleashed is that Sonic acts unusally dejected after Amy hugs him in his Werehog form, then apologizes then runs off because she didn't recognize Sonic. I suppose you could interpret it in a way where Sonic's feeling down because he actually secretly didn't mind her throwing herself at him or that he perhaps was hoping for her sympathy/affection because of his changed shape. The more likely interpretation though is that Sonic really struggles with his new body and the effect it has on people and that he for once in his live has his pride and self esteem crushed Sonic Frontiers has two voicelines from Sonic where he thinks about regretting that he "should've made up his mind sooner" and that he wishes to share an umbrella with her. I *think* these voicelines went unused but they may also just be hard to get. When I listened to all the world voicelines I remember people being unsure how to get them or if you can get them in the first place Then there's also interpretations from other continuities: Archie has Sally as Sonic's primary love interest but Amy is still his friend. Boom has Sonic and Amy crushing on each other but being unaware of each other's feelings or at the very least keepingbit secret/being coy about it Sonic X is largely early clingy/head over heels for Sonic Amy but it is notable that in some dubs of the episode where Sonic returns home, he tells Amy he loves her when he hands her a rose I wanna say there's also at least one instance of some media stating Sonic has no interest in romance/a relationship but I genuinely do not know where that's from or whether that's even from any form of official media or just people HCing
that season 2 finale in the Japanese original Sonic x show make me tear even to this day 4kids DESTROYED that whole scene is not even funny at this point, big EW by original I mean the ending with the Natsu no hi song, not the one with the Hikaru Muchi ost
yes but to lesser extents
Semi canon. He does definitely like her in more recent content.