Whats your favorite first song on a band's first album?

Mine is Hit the Lights by Metallica, from their debut album Kill 'Em All. It perfectly outlines their mission statement as a band: "we're going to kick some ass tonight", "we're going to blow this place away", "with volume higher than anything today". A good way to start off a long and storied discography.

Honorable mention to My Name is Jonas by Weezer.