“Rock With You” is the best Michael Jackson song, and I will take any disagreement as a challenge.
"Don’t Stop ‘Til You Get Enough" is a very good Michael Jackson song. There’s a nice syncopation to the beat, and the arpeggiated riff is infectious as hell. But I think it’s lacking in a few characteristics where "Rock With You" really excels:
Voice. I understand that falsetto is a Michael Jackson staple—maybe as a subtle, nostalgic nod to his Jackson 5 days—but there’s definitely such a thing as “too much of a good thing.” We only hear his non-affected singing voice, a youthful, soothing tenor, as a sort of harmony/scat part to “Don’t Stop.” Vice versa for “Rock With You:” where it lacks in classic MJ falsetto (which, granted at the time of Off the Wall’s release, wasn’t yet “classic MJ falsetto”), certainly makes up for it in plenty of room for him to showcase his vocal range.