It might be a bit of a cliché, but my pick would be Teenage Kicks by the Undertones. It’s such a perfect representation of its times, there’s a longing in the lyrics that I still feel every time I hear the song, and while not technically a masterpiece in terms of depth or skills, there’s nothing you could add or change that would make the song any better.
Or if a partial song counts, there’s of course that guitar solo by Prince around the 03:25 mark.
I hate the sound of Auto-Tune with a passion to the point where I want to break something when I’m being forced to listen to it.
Maybe that dates me, but I think that Auto-Tune is still exclusively used for its original purpose - make talentless twits sound less talentless.
If you can’t sing, just don’t sing. Don’t filter your voice through annoying effects until it’s unrecognisable. That’s the musical equivalent of drawing nothing but a dick on a test and failing it ‘on purpose’ because you couldn’t get a passing grade if you really tried, and trying to pass it off as acting cool. Either study/train harder or do something else, FFS.
I live in Switzerland, where downloading copyrighted material for personal use is legal, so your situation may differ. If I don’t find what I’m looking for in a DRM-free store, on eMule and on the high seas, I just download it from YouTube. The quality is not the best but usually sufficient. Try the NewPipe app on Android (if applicable) or https://de.savefrom.net/ - be aware that the latter should only be visited with a good ad blocker and antivirus.