https://www.youtube.com/watch?v=K6D5xpCgETk Nina Gordon from Veruca Salt covered Straight Outta Compton, just her, an accoustic guitar and her really high sweet voice, it's the greatest cover ever just for how funny it is.
If you think that's good, check out the Ben Folds' Five cover of "Bitches Ain't Shit". I love listening to re-recorded rap lyrics with music.
The Gourds - Gin and Juice https://www.youtube.com/watch?v=CrpdgD2SLRQ im learning it on mandolin, but its hard to sing and play at the same time.