This is a great, albeit somewhat ambiguous, thread. I was int the process of laying my record jackets out on the floor(and had some real contenders) before I realized that it is about cover songs and not album covers. Corrected and contrite, I submit: Marianne Faithful's cover of "Madame George" as my very favorites.
What is your favorite cover?
There are many great covers, such as Mr. Tambourine Man,by the Byrds. I'm curious about everyone's favorite.