Jonny Come Lately
The New Kid In Town
I really love both of these songs, and together they make a perfect one-two punch to open the album. I voted for Black Dog as I love the call-and-response structure, which gives the track a very distinctive feel, and the final solo is one of my favourite by Jimmy Page (I think John Paul Jones also deserves a lot of credit as I believe he came up with the great bass line underpinning the song).