Bob Dylan/The Band: Before The Flood
I bought this album as a gift for my brother one year, and then it turned out he already owned it, so I kept it. It was in my collection for a while and then I started to listen to it, and it is one of the main things that drove me into the singer/songwriter direction of musical appreciation.
Before I heard this album I was into the whole jam band thing, and never cared much for lyrics and music in terms of 'the song' rather then just the music.
If it weren't for this album as well as a few others, I would not be the songwriter I am today.
It is also one of the best live albums you could ever listen to, so listen to it.