Kelly Clarkson replaced Avril. Since Since U Been Gone came out and I was not impressed with most of TBDT, I never liked Avril as much, but I still like her.
Haha I remember in primary school when I'm a Slave 4 U by Britney Spears came out I was so scandalized! My little 10 year-old self felt to so betrayed by Brit-Brit ha new super-sexy image. I used her so hard during Oops...I Did it Again. I guess after a couple of years I replaced her with Bey during the Dangerously in Love era and haven't looked back since.