I think if you want to get lyrics tattoed on yourself, in memory/respect/love of Michael, get something that was written by him, personal to him.
As much as we all love the lyrics to songs like Man In The Mirror and You Are Not Alone, and we all know Michael totally owned those songs despite not writing them - I just feel maybe you might feel more happy to have something inked on you that Michael inked himself??
I hope that doesn't come across like me saying you shouldn't get MITM etc because he didn't write them or anything. Michael nailed that song, and meant every single word he sung. It's his song.
I don't know, I just think if it was me - i'd get something that he wrote from his heart. His exact words. Something he penned. A message he wrote.
Just my opinion though, I'd love to hear what you end up getting!
And at the end of the day,
what you get is what the tattoo means to you, and what he meant to you