5. BO BICE, ''In a Dream'' (Season 4)
Talk about cojones! Late in Idol's fourth season, when viewers knew things were coming down to a photo finish between country gal Carrie Underwood and Bice, the shaggy Alabama rocker set down the mic stand and delivered a searing a capella rendition of ''In a Dream,'' a little-known ballad by Badlands. Sure, Bice ultimately took home the silver — and his sales haven't come close to Underwood's multiplatinum heights — but it's impossible to forget (and it'd be criminal not to applaud) his bold artistic choice, which doubled as a nod to Idol's accompaniment-free audition rounds.

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