This is an amazing interactive look at the top songs on Billboard's "Hot Rap Songs" chart from 1989 to 2015:
It's by Matthew Daniels, who's ideas from his Journalist Engineer article are definitely shining here.
I didn't experience the earlier years on this chart which makes it really interesting to see which songs made it to my radar either through being timeless or classic, or even being passed on by my older sister.
I love how it's interactive, but I'm also content to just sit and let it do its thing. Very cool.