"...Insomniac was also the last time Green Day were a true punk band. Nimrod had its fair share of punk songs (including career highlight “The Grouch”), but it mostly saw them going in a lighter, more “rock” direction that got even lighter on Nimrod‘s 2000 followup, Warning. (And then they would come back four years later, fully reinvented as rock opera makers, with American Idiot. And the rest was not-very-punk history.) Insomniac closed the book on Green Day’s punk roots, and it’s still the best proof that Green Day really were just a great punk band, before the graduation ballads and the rock operas and the actual Broadway musicals. There’s also a good argument to be made that the pre-Dookie stuff — when Green Day were on Lookout! and playing shows at Gilman St. — was Green Day at their most punk, but as good as the early material (especially Kerplunk) is, their tools weren’t as sharp back then as they were on Insomniac. It might not be their most popular album, but it’s the one where everything just clicked and fell into place so quickly. It sounds better and less dated than its rawer predecessors, and it’s meaner and leaner than any Green Day album that followed. Of all the albums from the band’s classic ’90s run, it’s the one that sounds most fresh today."

- Andrew Sacher, Brooklyn Vegan