I never saw the Hollaback Girl video (above), but I totally dig the song. Apparently, it was the first non-hip hop, non-American Idol #1 single since 2001. Also news to me was that the song was inspired by none other than Courtney Love:
The inspiration for "Hollaback Girl" is generally ascribed to an insult from Courtney Love. Love had publicly accused Stefani of being a "cheerleader" for the music industry, essentially, an artistic sell-out. When asked about the composition's origins, Stefani responded (without mention of Love), "The song came about after somebody once called me a cheerleader in a negative light. So I said, 'well fuck you, I am a cheerleader, watch me on stage. I’m gonna make a big cheerleader song and you can fuck off.'"From Wiki.