"Just Like Tom Thumb's Blues" - Bob Dylan
Dylan turns 70 today. As we were discussing the other day, his song catalogue is so amazing and overwhelming in its breadth and quality that it's difficult to pick one as suitably representative. This one -- and this version particularly -- however, is my favorite for the moment. It's from the famous electric tour of England in 1966 and features the Band providing fierce musical backup. The guitar and organ playing here really nail this song.
I recommend the current version of Rolling Stone, which has a feature on the Top 70 Dylan Songs in tribute. It gives you a sense of the man's artistic scope.
Feel free to add your favorites to the list.