Stars on 2012's Time 100 list

Time magazine's 2012 list of the 100 most influential people in the world features several entertainers -- ranging from Rihanna to comedian Louis C.K. This year's categories included breakouts, pioneers, moguls, leaders and icons. Here is a look at the celebrities who made this year's list, featuring excerpts from guest Time magazine contributors.

Adele

Pink on Adele: "Turn on any radio station in the world and you will probably hear Adele. Go to Mars right now and I'm pretty sure if there is life on that planet, they're playing Adele. And for good reason."

Sarah Burton

Sarah Jessica Parker on fashion designer Sarah Burton: "She is a young woman who shouldered an enormous burden and privilege with dignity, heart and strength. She was the right hand of Alexander McQueen, known as Lee, a beloved designer and man; she was a secret to many, a secret weapon to one."

Louis CK

Joan Rivers on comedian Louis CK: "What you see on Louie is just the tip of the iceberg: a funny, clever show. What you're not seeing is that he produces it, he writes it, he edits it, he knows every lens, every camera angle."

Raphael Saadiq

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Elton John on Raphael Saadiq: "He contributed so much to the music, and we had a ball! His presence is already massive. It will only increase, and rightfully so."

Chelsea Handler

Kathy Griffin on Chelsea Handler: "Few women in comedy have gotten the attention and respect of the Establishment. Chelsea has, while being raw, hilarious and unafraid to cross the line and take it from me, that combination doesn't always go over."

Sharmeen Obaid-Chinoy

RIZWAN TABASSUM: RIZWAN TABASSUM/AFP/Getty Images

Angelina Jolie on filmmaker Sharmeen Obaid-Chinoy: "Pakistan's first Oscar belongs to a monumental campaign that is changing the legal, social and political fate of survivors of acid-related violence. Sharmeen Obaid-Chinoy's documentary Saving Face brought Pakistan's acid-violence problem to the world stage."

Claire Danes

Valerie Plame Wilson on Claire Danes: "CIA analyst Carrie Mathison, played exquisitely by Claire Danes on Showtime's 'Homeland,' is exceedingly hard to like. She steals medication from her father, sleeps with married men and counts no close friends or even hobbies, with the exception of appreciating the complexity of jazz."

Rihanna

Stella McCartney on Rihanna: "She's one of the coolest, hottest, most talented, most liked, most listened to, most followed, most impressive artists at work today, but she does it in her own stride. She works hard, very hard."

Kristen Wiig

Judd Apatow on Kristen Wiig: "I remember seeing Kristen Wiig on her first episode of 'Saturday Night Live.' I don't remember the sketch, I just remember her. She was so confident and funny right out of the gate."

Howard Stern on Matt Lauer: "All people become newsworthy in his Matt-talk, and their stories take on great importance. I've questioned the relevance of the Lohan story, the Brinkley divorce and again, again, again, Kim Kardashian. But it all becomes news, something we want to hear from the Matt Lauer interview."

Viola Davis

Cicely Tyson on Viola Davis: "Her recent Oscar nomination for Best Actress in 'The Help' is a beacon for other aspiring actresses. I was privileged to work on this film and humbled that Viola believes my career has been a benchmark for hers."

Stephen Colbert

Garry Trudeau on Stephen Colbert: "How he can be so devastating and endearing at the same time I cannot say, but it sure wears well. Look for him to hold down this spot on TIME's list for years to come."

Sally Potter on Tilda Swinton: "Tilda Swinton prioritizes being over acting, presence over character. She is interested in the whole rather than the part and is happiest at the core of a film, embodying its deepest themes with the luminous, naked face for which she is known."

Jessica Chastain

Gary Oldman on Jessica Chastain: "When the French call something formidable, they mean tremendous, terrific, awesome. These are words that came to mind when I first encountered the work of Jessica Chastain, 30, during her performance as Salome in Al Pacino's remarkable film of Oscar Wilde's play."

Harvey Weinstein

Johnny Depp on Harvey Weinstein: "There are producers, and then there are producers. Harvey belongs to the latter batch. It's an elite club for those with the kind of maverick vision to bring such disparate films as 'Pulp Fiction,' 'Kids,' 'Finding Neverland' and umpteen others to the screen with equal aplomb."

Tim Tebow

Jeremy Lin on Tim Tebow: "Watching Tim Tebow play football, you can observe many things about his character. You see his fierce competitiveness, his strong work ethic and how he is a leader that his teammates trust and respect."

E L James

Time editor-at-large Belinda Luscombe on "Fifty Shades of Grey" author E L James: "Six months ago she was Erika Leonard, a mother of two who dabbled in saucy stories for the Web. Now she's E.L. James, publishing phenomenon, whose 'Fifty Shades of Grey' trilogy has deeply stirred booksellers, Hollywood and, apparently, many, many mothers."

Jeremy Lin

Arne Duncan on Jeremy Lin: "Jeremy Lin's story is a great lesson for kids everywhere because it debunks and defangs so many of the prejudices and stereotypes that unfairly hold children back."

Catherine, Duchess of Cambridge, and Pippa Middleton

LONDON, ENGLAND - APRIL 28: Catherine Middleton (R) her mother Carole and sister Pippa arrives at The Goring Hotel after visiting Westminster Abbey on April 28, 2011 in London, England. With less than 24 hours to go final preparations for the wedding of P — Christopher Furlong/Getty Images

Time's Europe editor Catherine Mayer on Duchess Kate and Pippa Middleton: "The Middletons have become avatars of aspiration. Other women aim to dress like them, to emulate their easy athleticism and their more problematic slenderness."

Ann Patchett

Elizabeth Gilbert on author Ann Patchett: "My friend the writer Ann Patchett is a woman of wisdom, determination, generosity and courage."