Garrett definitely needed to go... I hope he cleans up his obvious drug problem and redirects his energy. Unfortunately, Chickeze (Or Jacuzzi, as Simon "accidentally" called him) should have gone also, particularly after dissing Simon.
On the women's side, Amy definitely should have gone, but Joanne was nowhere near the worst. Unfortunately, "plus size model" and "American Idol voters" don't go in the same sentence.