According to this article the one who impressed him was Brooke http://nymag.com/daily/entertainment/2008/04/how_many_american_idol_contest.html
“According to the L.A. Times, the Lord himself has tagged the genially acoustic Brooke White as the one who impressed him the most...”
Here’s the link to the LA Times article http://latimesblogs.latimes.com/showtracker/2008/04/american-idol-4.html
TMZ has the spoilers up now:
http://photos.tmz.com/galleries/idol_top_6_perform#1
Syesha Mercado — “One Rock & Roll Too Many” from Starlight Express
David Cook — “Music of the Night” from Phantom of the Opera
Carly Smithson — “Jesus Christ Superstar”
Brooke White — “You Must Love Me” from the film adaptation of “Evita”
Jason Castro — “Memory” from Cats. FYI, the official title is NOT “Memories.”
David Archuleta — “Think of Me” from Phantom of the Opera.