I love Green Day! They are, in my opinion, the greatest rock band of all time! I first listened to them on Tony Hawk's American Wasteland, with their song, "Holiday", and it became my favorite song by them. :) There was another song by them called "Teenagers from Mars", which was a cover origally made by the Misfits, and I liked it, but they weren't called Green Day when they performed it. They performed it as one of their side projects, named The Network.
I want to buy either Dookie, American Idiot, or 21st Century Breakdown, because I happen to like all the songs form those albums. They are awesome. :D