Green Day didn't write Good Riddance, Billy Joe Armstrong did...when he was in another band (and quitting said band). It's really not even a "Green Day" song, since he's the only one who takes part in it (besides a cello/violin player, IIRC). Oh, and it sucks, too. Also...Blvd. of Broken Dreams is a rip-off (musically and the flow of the lyrics) of Tracy Chapman's "For My Lover" (listen to it on YouTube right here).
Thats a pretty big stretch. Sure, its similar, but definitely not a rip. If you look close enough, you can do that with most songs since they're all working with the same ingredients. Now Green Day's Hitchin a Ride was definitely from the Stray Cats, but that was sampled w/ permission.
Good find though, I wouldn't have thought Chapman and Green Day would have anything remotely similar.