'Dancing With The Stars' Judges Declare Their Favorite 2 Celebrity Contestants Ever On '20/20' (VIDEO)

Over the past thirteen seasons, judges Len Goodman, Carrie Ann Inaba and Bruno Tonioli have seen a lot of celebrity contestants come and go on "Dancing With the Stars." On a special edition of "20/20" (Mon., 10 p.m. ET on ABC), every aspect of this global phenomenon was explored, from editions in other countries, to behind-the-scenes inanity like spray tanning.

Perhaps the most interesting moment came, though, when the judges were asked to name which celebrities they thought were the absolute best. For every Master P and Steve Wozniak, there has been a celebrity that stood above the rest and impressed the panel.

Goodman chose a former winner as the over-all best dancer of all time, while Inaba chose a runner-up as the "all around best contestant," as she put it. No one argued that Nicole Scherzinger was the best dancer they ever saw from the celebrity side, but it was Gilles Marini who most impressed them.

Tonioli talked about how much he grew throughout his season, where he came in second to Shawn Johnson. It was an inspirational transformation, and they felt like their show maybe helped him find himself in a way he never had before.

"Dancing With the Stars" airs Mondays at 8 p.m. ET and Tuesdays at 9 p.m. ET on ABC.

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