I think they suck. They're just American faux punk soccer mom music.
i'm 100% with this guy, they make really horrible music, if you searched more you would find some way more deserving bands of their fame, green day broken down is so bad, the singing is HORRIBLE, guitar riffs are lame, bass = lol wut, and drums are the same thing every single time, i mean most generic awful music that i've heard in a long time. they are talentless and got really famous, almost like every band that makes it big, only in the 80s did talented mean anything to the general public, now Kie$ha get famous, lil wayne gets famous, they don't even have a live show where they don't lip sync, please save the music, listen to real stuff.
if your in it for the signing try bands like - circa surive, isles $ glaciers, stuff like that
if you in it for guitar - the faceless, necrophagist, decrepit birth
drums - nile, anything with Frost in it
bass- good luck finding anything that promotes bass unless you like primus