As one of the most frequently ousted bands recycling old melodies & riffs, I must say Green Day has good taste; Petula Clark’s “Downtown” has always been a favorite of mine. Green Day has also been found to cop a pleasant ascending guitar riff from the Kinks.
For “Waiting” Green Day used the catchy melody of the Chorus in “Downtown” for the verse. This sound-a-like comes across more as a conscious homage than a ripoff, most clearly when Billie Joe begins the second stanza with “Downtown, lights will be shining…”