Take the question any way you will. The beauty of humanity, the evil of humanity, the human mind, the best song humanity has ever created, anything works. You don’t even need to explain it! Actually, for the most part, not explaining it would be better…
Me first!
I couldn’t explain my line of thinking on this one if I wanted to. Something about it just feels very distinctly human, y’know?
Alright, now you go.
Handlebars by Flobots seems on point to me. Although The Greatest Man That Ever Lived by Weezer comes close
It’s My Life, and Livin’ On a Prayer by Bon Jovi, and Somewhere Over the Rainbow are just a few that also come to mind 
All of them.
“The End of the World” by R.E.M.
Everyone’s favorite Inika commercial song, Move Along.
I think it represents humanity because moving along is what humans do. We pick ourselves up and then carry on without letting the past consume us.
I think this song does a good job embodying history prior to knowing,
Also it was composed by a Welsh bloke.
Where do I even start? Here are two that I think encapsulate humanity:
The first movement made me actually-actually-cry when I saw it in-person.
Go to 4:00 to 4:49. Trust me.
Also, Fool by Cavetown and, surprisingly, Ray Charles’ version of America the Beautiful are pretty good ones as well.
The pina colada song/escape
You all know why.
Nowadays - “Bad Reputation” by Joan Jett (warning: it does contain mild language. Not quite words that start with f, but not child-friendly). This might just be me but I see a lot of people trying to look like criminals nowadays, as if that’s a good thing.
Don’t know why exactly, there’s just something about it