As American Idol’s ninth season lurches to a close, its ratings teetering dangerously, its producers, at some of their lowest moments, might be tempted to recall the words of P.G. Wodehouse’s protagonist in The Return of Jeeves. Gazing upon the misbegotten construction of Towcester Abbey, the hero muses: “You know what this house wants? An atom bomb, dropped carefully on the roof of the main banqueting hall.”

Click the Image to See Richard Rushfield’s Oddsmaking on Simon Cowell’s Replacement

Of course, an atom bomb is about to drop on American Idol: Simon Cowell will leave at the end of this season. As a consequence, Idol’s producers now face the fearsome task of filling the chair of television’s biggest star, and around whose personality television’s biggest show coalesced. It is their chance—probably their last chance—to revive the ailing juggernaut.

• View our coverage of American Idol Season 9 View our coverage of American Idol Season 9 This season’s lackluster contestants will be a memory soon enough. It is the visible, aching problem with the revamped judging panel (minus Paula Abdul, plus Ellen DeGeneres), the lack of chemistry among the jurists, that threatens to take down Idol’s future seasons.

Without his traditional sparring partner in Paula, Simon largely ignores the others—except to shoot some maybe-more-nasty-than-funny barbs Kara DioGuardi’s way. Randy Jackson continues to float along, seemingly on autopilot, while Ellen has proven to be a one-liner machine of little relevance, neither offering rigorous critiques nor stepping up to the role of fierce maternal defender previously filled by Abdul.

But all of this—for better or for worse—is about to change. In just two weeks, the panel will say goodbye to Simon, its cornerstone. While it had been originally expected that the announcement of his successor would be made before the season’s end, it now seems the question mark will linger into the summer.

Every week, there is a new rumor of who will replace Simon, from the ludicrous ( Howard Stern) to the promising ( Elton John). After speaking with varied Idol insiders, the main criteria they are seeking in the candidates are track records of creating successful musical careers, and real stature that can command the panel, and therefore the show.

With those conversations in mind, we thereby present the frontrunners, long shots, and wild cards whose names are being bandied about in the greatest talent hunt since David O. Selznick’s search for Scarlett O’Hara.

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Richard Rushfield is a four-year veteran of the American Idol beat and the author of a recent memoir, Don't Follow Me, I'm Lost.