My top two are: "Butterflies" and "Remember the Time."
Then I remembered that Jackson didn't actually write "Butterflies" -- Marsha Ambrosius, one half of the former group Floetry, wrote the song.
Here's the story of how Jackson discovered the song and made it his own, according to Songfacts.com:
Marsha Ambrosius of the English Neo-Soul duo Floetry wrote this ballad when she was still at school. She and her Floetry colleague Natalie Stewart ... met Jackson through John McClain, DreamWorks's senior urban executive, who also manages Jackson. MJ heard this song and decided he wanted to record it.
Jackson invited the two Floetry girls to the studio and asked for their input on the recording of the song. Natalie Stewart of Floetry told Yahoo: "It was incredible because he asked, he continually, asked, 'Marsh, what's the next harmony? Girls, does this sound right? What do you think? Is this what you were looking for? He was so open."
Marsha Ambrosius told Yahoo that it took a few minutes for her to calm down. She recalled: "To begin with, I was kinda shook. Because you don't realize how you're going to feel until you're put in that kind of situation. I had the tears in my eyes and got kinda nervous. But as I got into it, I realized it was work, it was a job. I had to vocally conduct a legend."
Ambrosius told VH1 that Stewart had a dream that the two girls were in a limo with Michael. She continued, "He was singing a song and it was like, 'Oh, I like that song.' A year later, we're in the studio cutting 'Butterflies' with Michael Jackson."
A year after this appeared on Invincible, Floetry's original version was included as a bonus track on the English version of their debut album Floetic.
Michael Jackson has said that this is his favorite song on the album.
Ambrosius has gone solo and is currently signed to Dr. Dre's record label, Aftermath Entertainment.
Here's Ambrosius singing this gorgeous song: