LOS ANGELES (Reuters) - The biggest stars of U.S. television will don their bow ties and finery on Sunday for an Emmy Awards gala shaping up as a farewell bash for America's favorite mob family, "The Sopranos."

HBO's landmark gangster saga, which ended its six-season run in June, is widely favored to muscle out its rivals and claim several top awards, including the first best drama prize won by an American series for its final season.

So strong is "Sopranos" sentiment that producers of the Fox network's telecast plan a goodbye tribute to the fictional New Jersey mob clan by the cast of Broadway musical "Jersey Boys."

But Emmy pundits caution that the lovelorn doctors of the ABC hit medical show "Grey's Anatomy" could end up crashing the "Sopranos" party with an upset victory for best drama.

"Grey's," upstaged in 2006 by the Fox spy thriller "24," also is competing with fellow ABC drama "Boston Legal," rival Fox medical show "House" and NBC superhuman serial "Heroes."

The battle for best comedy is considered a close race between three workplace-themed shows, with last year's winner, "The Office," narrowly favored over low-rated fellow NBC contender "30 Rock" and the new ABC hit "Ugly Betty."

Rounding out the comedy nominees are hip HBO Hollywood satire "Entourage" and bawdy CBS sitcom "Two and a Half Men."

In the category of best competitive reality show, the Fox talent search "American Idol," the most watched show on U.S. television, is expected to finally get its due.

"Idol" has been nominated for top reality show the past four years and beaten every time by "Amazing Race." A win this year would be especially welcome to Fox and "Idol" producers, given the network is hosting the telecast emceed by "Idol" host Ryan Seacrest.

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HBO's made-for-TV movie "Bury My Heart at Wounded Knee," about the 19th century decline of native American culture, is expected to dominate its category as the year's most decorated Emmy contender, with 17 nominations in all.

One obscure Emmy honor drawing attention this year is the "interactive television services" award, which is expected to go to Al Gore's fledgling cable/Internet venture, Current TV. The former U.S. vice president won an Oscar this year for his eco-documentary "An Inconvenient Truth."

However, the main focus remains "The Sopranos" and its 15 nominations, the most for any single TV series this year.

Emmy watchers predict James Gandolfini will nab his fourth win for best dramatic actor playing conflicted mob boss Tony Soprano, whose fate was left murky by the notoriously abrupt blackout ending of the show's final episode.

But Gandolfini is getting a run for his money from Hugh Laurie, the British actor who plays the brilliant doctor with a miserable bedside manner on the Fox network hit "House."

Edie Falco, who has three Emmys for playing Tony Soprano's long-suffering wife, is slightly favored to win as best actress in a drama. But she could be upset by Kyra Sedgwick for playing a cop on TNT's "The Closer" or Minnie Driver, nominated for her role a con artist in the new FX cable series "The Riches."

Among comedies, America Ferrera is seen as a near shoo-in to claim an acting Emmy as the homely but indomitable fashion magazine assistant on "Ugly Betty." The race for best actor in a comedy is dominated by two stars playing bosses from hell -- Alec Baldwin for "30 Rock" and Steve Carell for "The Office."