Let's post our favorite song covers! Make sure to include both the cover as well as the original version of the song (Kinja allows you to post more than one video in a single comment), so we can compare them. I'd also be interested in knowing what it is about the cover that you think makes it particularly good.
For me, a really good cover does something new and interesting with a song, while still honoring the spirit of the original. I think Madeleine Peyroux's cover of "Between the Bars" by Elliott Smith is pretty much perfection in this regard.