David Cook (season 7, winner)
Sure, David Cook totally rocked Bon Jovi's ''Living on a Prayer'' in his audition, but it was hard to concentrate on his singing with what looked like a rooster sitting on top of his head. And that argyle sweater. No. Just no. His style screamed poser, but that would change at one pivotal moment during the finals: when Cook debuted his New Hair on top 9 Country Night. Goodbye, bad comb-over. Hello, hotness! Once again, concentrating on his exquisite cover of Dolly Parton's ''Little Sparrow'' was toughbut this time for all the right reasons.