All Grammys are not created equal. While 1,100 nominees are vying for 108 trophies, one contest trumps the rest for prestige, pizzazz and PR power: album of the year.

Music's most coveted prize, an anointing of artistic merit that can also reignite sales, brings five diverse candidates into a tight race decided by a notoriously illogical voting body.

The results will be revealed at Wednesday's Grammy Awards. The five albums in play are U2's "How to Dismantle an Atomic Bomb," Kanye West's "Late Registration," Mariah Carey's "The Emancipation of Mimi," Gwen Stefani's "Love.Angel.Music. Baby." and Paul McCartney's "Chaos and Creation in the Backyard."

They're listed in the order that Paul Grein, music writer and veteran Grammy prognosticator, believes the voters will rank them. The criteria? Popularity, artistry, sales, lovability, history and mysterious ephemera.

"I think U2 will win," says Grein, countering a consensus leaning toward West. "Three albums have a shot. Kanye is second, Mariah is third. I've got to believe U2 will take it. They're so respected, and they stand for the traditional pop-rock craft that has always done well in the Grammys going back 35 years."

Those in West's corner argue that "Registration"'s unprecedented praise, nongangsta stance and big sales make it a shoo-in, and that its chances are further enhanced because the rapper's "College Dropout" was cheated out of a best-album win last year.

"It's hard to see Kanye winning when just a year ago he couldn't beat Maroon 5 for best new artist," Grein says. "There's still resistance to rap."

Though a win for West would be a milestone, it's not a Grammy first. Hip-hop duo OutKast won best album two years ago.

"Rap got over that hurdle and set a precedent," Grein says. "But OutKast faced very weak competition. If Kanye does win, it would be a much more convincing statement about rap's appeal. He would be beating a Beatle, the most respected band since The Beatles and the year's biggest-selling album."

PAUL MCCARTNEY

ALBUM: "CHAOS AND CREATION IN THE BACKYARD"

Sales and airplay: "Chaos" has sold 465,000 copies since its release Sept. 13, according to Nielsen SoundScan. McCartney failed to register in any Nielsen BDS year-end radio-format airplay charts, falling well behind teen idol Jesse McCartney.

Touring boost: McCartney had the fifth-highest-grossing tour in North America last year, with gross revenues of $60 million, according to Billboard BoxScore.

Grammy clout: McCartney is also up for male pop vocal and pop vocal album. He has won 13, though none for his work outside The Beatles or Wings. His last best-album trophy was in 1968 for "Sgt. Pepper." He won pop and video Grammys in 1997 for "The Beatles Anthology."

Grammy tilt: Voters adore icons and often anoint underrewarded artists with "makeup" awards, but Grein sees no such scenario. "The Beatles should have won more Grammys, but McCartney got a lifetime achievement award. This can't be called a comeback, because he's always in the game. It's one of the strongest albums he's made in 20 years, but a good album by a pop legend is not reason enough to win this."

MARIAH CAREY

ALBUM: "THE EMANCIPATION OF MIMI"

Sales and airplay: "Mimi," the top-selling album of 2005, has sold 5.1 million copies since its release April 12. "We Belong Together" was the top national airplay song of 2005; "Shake It Off" was No. 6 and "Don't Forget About Us" was No. 38.

Touring boost: Carey managed to keep a high profile in 2005 without hitting the road.

Grammy clout: Carey's up for seven other Grammys, including best record and song. She won best new artist and pop female vocal in 1991.

Grammy tilt: "Mariah is strong, because she had the year's No. 1 album and nobody thought she could come back anywhere near this level," Grein says. "This is an unforgiving business, and once your name's a punch line, it's almost impossible to come back. But (modern) R&B isn't a favorite kind of music for a lot of Grammy voters. Traditional R&B is more respected. So a win would be a surprise."

U2

ALBUM: "HOW TO DISMANTLE AN ATOMIC BOMB"

Sales and airplay: "Bomb" has sold 3 million copies since its release Nov. 23, 2004. U2 did not have widespread radio success with the album, but "All Because of You" was the No. 49 modern-rock song of 2005; "Vertigo" was No. 50.

Touring boost: U2's Vertigo Tour trampled the competition, with global grosses exceeding $260 million. The band earned $123.2 million playing to 1.2 million fans at 69 sold-out U.S. dates.

Grammy clout: U2 is up for four other Grammys, including best song. "Bomb" also generated two Grammys from three nominations last year. The band has 16 Grammys but hasn't won best album since 1988 for "The Joshua Tree."

Grammy tilt: Out nearly 15 months, "Bomb" may feel dated to voters. All other elements point to victory. U2 pleases modern and old-school camps. The band has artistic relevancy and earning power. Bono's humanitarianism is a plus. "As in all awards competitions, voters look for ambassadors for their art form, and U2 make great ambassadors," Grein says.

KANYE WEST

ALBUM: "LATE REGISTRATION"

Sales and airplay: "Registration" has sold 2.5 million copies since its release Aug. 30. "Gold Digger," despite a July debut, was the nation's No. 4 song last year.

Touring boost: West's fall tour with Fantasia and Keyshia Cole grossed $8 million for 44 U.S. dates. All but seven sold out. He also opened four U2 shows in December.

Grammy clout: West won three Grammys last year for rap album, rap song and R&B song, but his highly praised "College Dropout" lost in best album to Ray Charles' "Genius of Soul."

Grammy tilt: Even considering Grammy's conservative tastes and reservations about hip-hop, "Kanye is in the race," Grein says. Ego and arrogance could factor into a loss. "A few years back in their acceptance speech, U2 made a generous statement about Destiny's Child," Grein says. "It was classy. Kanye is a brilliant artist, but he might do well to learn that modesty and class can carry you a long ways."

GWEN STEFANI

Album: "Love.Angel.Music. Baby."

Sales and airplay: The album has sold 3.6 million copies since its release Nov. 23, 2004. Stefani is the first artist in more than a decade to score six mainstream top 40 hits from one album; "Hollaback Girl" was No. 10 overall for 2005.

Touring boost: She sold out 16 of 30 U.S. dates, performing to 328,000 and grossing $17.4 million.

Grammy clout: Stefani is up for four other Grammys. As a member of No Doubt, she won two pop Grammys in 2003 and 2004. She and Eve shared a rap Grammy in 2002.

Grammy tilt: Despite her high nomination count, she's likely in last place in this race, Grein says. "I don't think she has a chance," he says. "It's a successful debut album by someone they like, sort of in the same ballpark as Justin Timberlake a couple years ago."