I read somewhere that in the last twenty years there's only been three albums that changed (or at least altered) the state of rock due to not only the album's impact, but also what became "cool" and "uncool" after the album's release. Is This It, Nevermind and Appetite for Destruction.
"Is This It" easily is the weakest of the three in terms of sales and most of the general public probably can't even hum "Last Nite" but the guitar bands that suddenly got attention because of the Strokes and the hype are numerous.
Brian