21. Operation Ivy, 'Operation Ivy' (1991)
"Everyone's got their band," Billie Joe Armstrong told Spin in 2005, "and I've got to say Operation Ivy was definitely one that changed me." The Green Day lead singer wasn't the only one whose life was changed by the band that included future Rancid members Tim Armstrong and Matt Freeman; for better or worse, the outfit could be thanked for the entire ska-punk sound that they left in their wake. But taken on its own merits, the their entire studio discography of less than 30 songs (collected on a self-titled 1991 Lookout Records comp) pulses with youthful energy, anger and urgency, all set against a raw, poppy sound that countless bands would try to imitate, but none could duplicate. The band epitomized the scrappy East Bay scene that spawned Crimpshrine, Mr. T Experience, and, of course, Green Day, who would record a honky tonk-style cover of Op Ivy's "Knowledge" on their second seven-inch. J.D.