It's no surprise that this lead single off Justin Bieber's debut album, "My World 2.0," is No. 1 on the most searched lyric chart. The up-tempo R&B number with doo-wop elements has become a worldwide Top 10 hit -- and the Canadian-born teen pop idol's highest-charting single in the United States -- and its video is one of the most viewed in YouTube history. Could we chalk up its success to Bieber-licious dance moves in the video, or to the fact that he looks so "Baby"-ishly adorable, even while coming up a few inches shorter than his female lead?

Ludacris's rapid-fire rap on puppy love lends an ounce of urban street cred to a tune crafted by Christopher "Tricky" Stewart and Terius "The-Dream" Nash (co-writers of Bieber's first hit, "One Time") and Nash's then-spouse Christina Milian. Bieber himself does a spot-on job on the track's supple, R&B-steeped vocals, which recall the young Michael Jackson's emotion-packed falsetto. Though, word is that the 16-year-old sings the song live in a new key: His voice is changing, and he can no longer hit the high notes.

But puberty hasn't completely put the kibosh on "Baby" -- add Bieber's attempts at moonwalking in the video, and fans scored a tune that directly taps into Jackson's legacy. The allusion is not lost on Ludacris, who described the video as "a 2010 version of Michael Jackson's 'The Way You Make Me Feel.'" Overshadowed by the performance and the effortlessness of the hook, the lyrics of "Baby" are nothing to write home about. They say nothing about JBiebz himself -- but they may offer insight into all the fans on Team Bieber who want to be the parent-friendly idol's baby.

--Kimberly Chun

Few would have suspected that the hot-headed, brilliant rapper who lyrically lacerated his twice-divorced ex-wife Kim would find chart-topping satisfaction with this eloquent hit single, one of the most accessible, albeit troubled, romantic numbers in his career. From Eminem's seventh full-length album, "Recovery," "Love the Way You Lie" is fictional, but the man born Marshall Mathers clearly identifies with the anger and self-hatred of his narrator.

The father of three daughters told Rolling Stone in a November 25 cover story that he continues to grapple with his lack of trust toward women. Unlike other Eminem tracks that bandy violent themes with cartoonishly over-the-top imagery or gross-out black humor ("'97 Bonnie and Clyde"), "Love the Way You Lie" looks straight at the switchback duplicity of its tortured, anguished teller. Alternately defensive and conciliatory, the song has a total absence of irony and a gravity that reflects the now two years-plus clean-and-sober Em, with spare piano, acoustic guitar, and dead serious strings. The narrator says, "I love you too much / To walk away though / Come inside / Pick up your bags off the sidewalk / Don't you hear the sincerity / In my voice when I talk / Told you this is my fault /  Look me in the eyeball / Next time I'm pissed / I'll aim my fist / At the dry wall / Next time / There will be no next time / I apologize / Even though I know it's lies."

Eminem's emotionally pointed and psychologically precise rap pushes forward in raw contrast to the melodic elegance and ache of Rihanna's vocal hook. Her part hinges on the double entendre foregrounded in the video starring Megan Fox and  Dominic Monaghan of "Lost." They play a couple caught in bedroom repose when not entangled in game-playing lies, playing out a mutually destructive tryst that burns so hot, it threatens to engulf them. Of course, Rihanna's personal backstory -- her 2009 pre-Grammys assault by then boyfriend Chris Brown -- brings an almost masochistic dimension to her verse: "Just going to stand there / And watch me burn / But that's all right / Because I like / The way it hurts." All elements conspire to make the song Eminem's fourth No. 1 and Rihanna's sixth, tying her with Mariah Carey, Beyonce, and Lady Gaga as an artist with the most No. 1s in Billboard's history.

--Kimberly Chun<.em>

A standout among 2010's Most Irresistible Lyrics for its negative hook about the perverse turns that love can take, "Bad Romance," the lead single from 2009's "The Fame Monster," summons the synth-driven polished pop of "Vogue"-era Madonna, as well as Lady Gaga's own unique sonic fingerprint. Witness the rave-friendly dance-floor beats, house and techno flourishes, the sing-along chorus that wallows in the stupid-brilliant kitsch of nonsense words, and the complicated view of consensual romance, one that's as twisted and changeable as the many structural switches in the song. "I want your horror, I want your design / 'Cause you're a criminal as long as you're mine ... I want your Psycho, your Vertigo schtick / Want you in my Rear Window, baby, you're sick," warbles Lady Gaga, referencing Alfred Hitchcock shock and awe in cinematic free-association.

Deep in the mix, she shrieks, "I'm a freak, baby!" -- just daring Gaga groupies to keep their poker face on straight. In the video, the artist's anime-eye contacts, Alexander McQueen armadillo stilettos (she premiered "Bad Romance" at McQueen's spring-summer 2010 show), and charred post-coital finale bolster the freakiness. The inexorably driving beat almost makes the listener forget exactly what the song -- Gaga's second-biggest single after "Poker Face" and one of the best-selling singles of all time -- is about: namely, as Gaga told Grazia magazine, being in love with one's best friend. Leave it to Stefani Germanotta (who says she coped with being called both "the Germ" and "Big Boobs McGee" in high school) to tackle a love song in her very own way: the Hitchcock comes in, she told Alexa Chung, because "I want the deepest, darkest, sickest parts of you that you're afraid to share with anyone because I love you that much."

--Kimberly Chun

As Sunshine Corazon on "Glee," Charice (born Charmaine Clarice Relucio Pempengco) shines like a fiery orb -- if the sun were a petite Filipina singer emitting flame-throwing powerhouse vocals. With "Pyramid," the singer takes her homegrown yet polished breed of gospel-tinged pop-R&B out to play, gaining mainstream radio airplay and a big hand from Oprah Winfrey, who dubbed her the "most talented girl in the world." The lyrics of "Pyramid" don't venture further than assurances that "We took it from the bottom up / And even in a desert storm / Sturdy as a rock we hold / Wishing every moment froze." Such potentially forbidding metaphors are dispelled by the 18-year-old's feisty, soul-stirring performance -- and a charisma, on full display in the song's video, that sweeps away doubts.

The first Asian artist to land in the Top 20 of the Billboard 200, Charice has been steadily building on her YouTube success after getting into the finals of "Little Big Star," an "American Idol"-esque talent show in the Philippines. Said to have been informally trained by her single mother, Charice might be best known for her rugrat-set cameo in "Alvin and the Chipmunks: The Squeakquel." But she's already realized more than a few dreams, including singing with her idols, Andrea Bocelli and Celine Dion.

--Kimberly Chun

Bruno Mars (born Peter Hernandez) took his initial turns in the pop spotlight singing the sweetly melodic, breezy vocal hooks on B.o.B.'s "Nothing on You" and Travie McCoy's "Billionaire," both songs he co-wrote and co-produced. In his first major hit, "Just the Way You Are," he went a less doo-wop route (despite the title of his debut full-length, "Doo-Wops & Hooligans"). No, the track is not a Billy Joel cover but a simple, seemingly guileless love song, written by the Smeezingtons -- Mars's production and writing group with Philip Lawrence and Ari Levine -- along with Khalil Walton and Needlz.

Rapper Lupe Fiasco pops up in the remix, but the original version of this disarming pop number isn't without a piquant hip-hop flavor, fueled by a frisky snare and a crackling vinyl sample. Background whistling references the lighthearted "Young Folks" by Peter Bjorn and John. The lyrics aren't extraordinary: "Yeah, I know, I know / When I compliment her / She won't believe me / And it's so, it's so / Sad to think she don't see what I see / But every time she asks me, 'Do I look OK?' / I say, /  'When I see your face / There's not a thing that I would change/ ‘Cause you're amazing / Just the way you are." But the sentiment is eternally winning, especially with ladies accustomed to being led around by their insecurities.

For this No. 1 platinum song, the Honolulu-born Mars aims to please. And the song is true to form for a singer-songwriter and producer who grew up impersonating Elvis Presley and rock-pop idols such as Michael Jackson, inspired by a '50s rock fan father who ran a Waikiki memorabilia store devoted to the King.

For a little more dangerous song from Mars, look to the saucy viral hit he co-wrote for Cee-Lo Green, "F--- You." Or his risk-taking take in his latest single, "Grenade,"

--Kimberly Chun

"The Simple Life" is long gone for Ke$ha, who first jettisoned into the eye of pop-culture cultists on the Paris Hilton-Nicole Richie reality show. A one-time vocal contributor for Britney Spears and Flo Rida, Kesha Rose Sebert now has the cash -- and flash -- to go with the dollar sign in her stage name: bona fide club classic "Tik Tok." Ke$ha's debut single has become the seventh best-selling download in digital history, scoring the highest weekly download sales ever by a female artist.

Blame its party-girl dance-pop popularity on its wake-up-call squeezebox rhythms, video game electronic textures, and K-Money's sassy raps, name-checking P. Diddy and Mick Jagger and drawling, with an inaudible slur, "Before I leave, brush my teeth with a bottle of Jack / 'Cause when I leave for the night, I ain't coming back." Ke$ha's high times have inspired love: She has performed the song on "The Tonight Show with Conan O'Brien," "Today," and "The Ellen DeGeneres Show," and it has been used in "Project Runway," "Melrose Place," "The Hills," "Percy Jackson & the Olympians: The Lightning Thief," the Miss Universe 2010 competition.

But she's also inspired parodies, both low-tech and viral (i.e., the Israel Defense Forces' "IDF Tik Tok" dance video), as well as haters. Apparently an out-of-control girl who just wants to have fun runs the risk of viral shutdowns.

--Kimberly Chun

Tortola, British Virgin Islands, native Iyaz is poised to become 2010's musical MVP for his collaborations with young female pop stars. He worked with Charice on "Pyramid" and Hannah Montana (aka Miley Cyrus) on "Gonna Get This." "Solo," much like his compulsively singable hit "Replay," presents the U.K. chart-topper as more than just a side guy.

In his second single, Iyaz (aka Keidran Jones) obsesses over a childhood sweetheart -- a switch from the finicky iPod of his first hit. With producer J.R. Rotem, the singer contemporizes his island riddims with a heavy dose of electronics, updating samples of Janet Jackson's heart-tugging "Again" with a slew of kitchen-sink synth embellishments. Handclaps, faux laser blasts, and trebly beats skitter across the pleasing surfaces of Iyaz's airily youthful vocals in a self-consciously nostalgic shout-out to yesteryear's R&B. Our beach boy wanders his homeland's shoreside spots in the track's video, bemoaning the long-ago loss of a schoolgirl love. "I don't want to walk this earth if I gotta do it solo," he begs sweetly.

Happily, Iyaz doesn't have to -- at least in the video -- closing the clip with a stroll across the sands with a delectable new hottie. Intriguingly, in the context of Iyaz's career, the song seems to play it both ways: The lyrics cry out for togetherness, although the arrangement's emphasis on the word "solo" sounds like it's making a bid for Iyaz as a singular artist, unattached to any pop ingenue. The singularity is a legit assertion, considering that "Solo" is Iyaz's second U.S. Top 40 hit, and he appears to have a charmed future: Akon and Wyclef Jean are said to be collaborating on his upcoming album.

--Kimberly Chun

No, it's not about Boys Like Girls frontman Martin Johnson's rumored romance with Taylor Swift, although she contributes girlish harmonies to the alternative rock-country pop tune, the Boston band's second platinum single. Read the title of "Two Is Better Than One" as a reflection of the circumstances in which Boys Like Girls made its accompanying album, "Love Drunk": Half was recorded in New York City, half in Vancouver, with two different producers, production teams, and approaches.

Two heads or two hearts -- regardless, one can picture the ladies swooning for this lovestruck emo-pop midtempo number, replete with plucky strings, full-bodied orchestral arrangements, and sensual details. Swift wistfully sings, "I remember every look upon your face," and Johnson adds, "The way you roll your eyes / The way you taste / You make it hard for breathing." Gasp. True to their name, these veterans of that punk-pop live pachyderm, the Vans Warped Tour, aren't afraid to let their soft side show, even while fielding disses from critics such as Allmusic's Tim Sendra, who called "Two Is Better Than One" "something Diane Warren would have shelved for being too trite and formulaic."

--Kimberly Chun

The dry spell is over for the San Francisco Bay Area alternative-rock band Train. "Hey, Soul Sister" marked the end of a nine-year Top 10 drought, coming in at No. 3 for four weeks in 2010, making it the ever-loving, still-chugging combo's highest-charting yet. With more than 4.5 million legal downloads under its belt, the quadruple-platinum track also distinguishes itself as the most downloaded song in Columbia Records history and the 14th most downloaded song ever, according to NielsenSoundScan. The merrily spare mandolin at the heart of the tune tips its cap to the minimalist ukulele trend coursing through San Francisco's indie rock scene, while vocalist Patrick Monahan's lyrical references to Madonna, "Love Connection," and Mr. Mister unabashedly foreground his, erm, youth, as well as the still-au-courant '80s.

Consider "Hey, Soul Sister" a homecoming -- and centerpiece love letter -- in an album titled "Save Me, San Francisco," four years in the making and aimed straight at Train's roots. Monahan isn't afraid of playing the goof, with his heart firmly pinned on his sleeve, as he plaintively wails, "You're so gangsta, I'm so thug, you're the only one I'm dreaming of / You see, I can be myself now finally, in fact there's nothing I can't be / I want the world to see you be with me." Apparently San Francisco -- along with the rest of the world -- came through.

--Kimberly Chun

With unshowy vocals that cue thoughts of heart-baring emo longing, and delicate synths that conjure up memories of '90s-era indie electronic outfits such as American Analog Set, the triple-platinum "Fireflies" received the big boost its predecessors didn't when it was covered by everyone from Lee DeWyze on "American Idol" to Kidz Bop. It also helped that bedroom-basement rocker Adam Young flew into view as something of a MySpace sensation, and the buzz nabbed him a deal with major label Universal Republic.

"Fireflies," the debut single by Young's project Owl City, concerned insects and insomnia. Probably few dreamed it would become an anthem for a new generation, as an audience sing-along at one Owl City show, documented in a promotional video, demonstrates. The buzzable "Fireflies" is also one of the more unusual, intimate-sounding songs on our Most Irresistible Lyrics list: "I never really had anything I wanted to say, to anybody," Young says modestly in his label's promo video. "But there's always been a mood I wanted to convey via sound, which is optimism."

Fittingly, the unorthodox "Fireflies" is also one of the few tracks with heavily searched lyrics that isn't a love song. Instead Young touches on existential issues like the losses of youthful innocence and of connection with the natural world in the rush to grow older. "I'd like to make myself believe / That planet Earth turns slowly / It's hard to say that I'd rather stay / Awake when I'm asleep / Because my dreams are bursting at the seams," croons the Owatonna, Minnesota, musician, who went from toiling at a Coca-Cola warehouse to contributing to the soundtrack of the owl-heavy "Legend of the Guardians." Those thoughts have certainly resonated with both youngsters and young-at-hearts.

--Kimberly Chun