There's so many. Where to begin.
Where The Streets Have No Name - U2
Battery - Metallica (First Metallica song I heard. Was totally blown away when the song 'changed' to the metal riffs)
She Sells Santuary - The Cult (Has to be the long version. Builds up the anticipation)
Welcome Home - Coheed and Cambria
Blitzkrieg Bop - Ramones
Everlong - Foo Fighters
Best non-intro
The Wagon - Dinosaur Jnr. (Straight into the action, no meesing about)