I really love covers. I think that one of the most interesting things to listen to is a new version of a song that you know.
So, when, 1-2 years ago, a few rock artists began releasing covers of (terrible) rap music, I was immediately a fan.
A few favorites:
The covers of rap songs are 75% parody (much higher for the Alanis Morisette one) and 25% genius.
In the vein of covers, though, one I have been listening to rather a lot lately: