As much as ld hate to say it, green day has really made punk a big genre, one of the biggest in our time right now. seems like most bands want to sound punky and what not, and hey thats cool, if its what you want to do. green day is a band that i really dont like, but i know that their very talented.  Alot of singers in the bands try to imitate billy. try to get the same sounding guitars and what not. and they accomplish it its not hard to do. punk is very popular in this day and age alot more then when it first originated. it seems like the style has not changed at all though from back when it was created.  most of the riffs that they play tend to be rather simple and very repetitive and thats really what i dont like about it, to easy for me.