This all depends on what media you get your information from. There isn't really a wrong or right answer. In the Archie Comics, Sonic obviously dislikes Amy, and sees here merely as a friend, and even if they were to get together, it would be odd considering Amy is actually many years younger than Sonic.
According to Sonic X, Sonic loves Amy, of course, Sonic doesn't outright say it (aside from the French version, in which Sonic literally says he loves her). But it's shown many times that he has hidden feelings for her, such as the episode: The Last Resort, also, it is apparent that they're an actual couple Season 3 onward.
Now, according to actual in-game canon. It's impossible to know. However, according to Sega of America, Sonic loves her. Plus there are instances in the series in which Sonic's liking for Amy shows, such as in Sonic Unleashed in which Sonic becomes depressed when Amy thinks she mistakes Sonic's Werehog form for someone else. There is also the instant in Sonic and the Black Knight, at the end in which Sonic and Amy apparently had a scheduled date. Also, according to Sega, Amy's reason for being (in Sonic CD) was to provide Sonic with a girlfriend.
This is all evidence towards Sonic loving Amy, but it's still all very debatable until Yuji Naka or some other high ranking Sonic Team executive comes out saying so.19:40, December 8, 2012 (UTC)