Carrie Underwood voted most popular 'Idol'

Kelly Clarkson comes in second in AOL TV poll

Country singer Carrie Underwood is the all-time most popular "American Idol" winner, and dreadlocked Jason Castro was voted the most overrated contestant this season, according to a poll released on Monday by AOL Television.

With the most watched U.S. television show reaching its climax this week, finalists David Archuleta, 17, and David Cook, 25, are running neck and neck in terms of best performances of the seventh season, according to the poll.

Archuleta's rendering of John Lennon's "Imagine" in February was rated best of the season by 35% of those taking part, with Cook's rock version of the Michael Jackson hit "Billie Jean" in March also getting 35%.

The AOL Television poll, conducted May 9-16, received more than 1.3 million votes.

Underwood, the 2005 "American Idol" winner who went on to win Grammy, American Music, Billboard and Country Music Assn. awards, was voted the most popular "Idol" by 54% of those taking part.

Kelly Clarkson, who won the first season in 2002, was second with 26% of votes.

Castro, the mellow guitar-playing Texan who made it to the final four round of contestants this year, topped the list of most overrated singers of the 2008 season with 28% of votes. Some 35% rated his performance of the Bob Dylan classic "Mr. Tambourine Man," in which Castro flubbed the lyrics, the worst of the year.

An overwhelming majority -- 63% -- thought that contestants who had record deals in the past should not be allowed to compete on the Fox network show. The thumbs down reflected the controversy over sixth-place Irish singer Carly Smithson, 24, who got her second chance to make a career in the music industry after a record deal nine years ago went nowhere.

Australian Michael Johns, 29, was considered the 2008 "Idol" loser most likely to make good, despite being eliminated five weeks ago.

Some 63% said they had purchased contestant performances from iTunes -- the first year that music from the show has been available for download from the online service during "American Idol" broadcasts.

Archuleta and Cook will sing for the 2008 "American Idol" title and a recording contract on Tuesday. The winner will be announced in Hollywood on Wednesday.