As far as I know, this is the best music video ever by a single ("Question" by Justin Hayward):
The Moody Blues - Question - Live at the Rock´n Roll Hall of Fame - YouTube
But then maybe you have something you like better that you'd like to share.
PS: Trollheart brought to my attention in the next post that I didn't make it clear that I was talking about a single artist, not a single release from an album.