I voted for Whatever Happens as I love everything about it: the melody, the lyrics, the mood and it has the most balanced production for me.
I agree though that Speechless has the most amazing vocals, I just wish the instrumentation was more stripped down, sort of acoustic to convey better the vulnerable and... well, speechless feel to it.
Break Of Down could be also perfect for me with MJ only background vocals.
Butterflies is a beautiful song with great vocals that I appreciate a lot, but the style isn't really my cup of tea.
I consider The Lost Children a good song too with an important topic so dear to MJ.
And I must confess that although it's quite an average song I can't help but like Cry, the melody is just so nice to my ears, I always have to hum along when I hear it.
Hmmm, reading through this there isn't such a big problem with the ballads on Invincible after all (which has been my impression). Maybe it's just that there's too many of them on one album and not well-sorted.