Rickman played Severus Snape in all eight of the "Harry Potter" films. The noted British actor enjoyed his greatest awards success playing the title role in the 1996 telefilm "Rasputin" winning the Emmy, Golden Globe and SAG Award. He has yet to contend at the Oscars

Brooks is a veteran actor and writer best known for his comedy work -- including his Oscar-nominated supporting turn in "Broadcast News" -- so his against-type performance as a menacing criminal in "Drive" may be even more impressive to Oscar voters, but his chances may be affected by how widely the film is embraced as a whole.

"Rise of the Planet of the Apes" received strong reviews and earned almost half a billion dollars worldwide. Receiving the most attention was Serkis for his performance as Caesar, a chimp who develops enhanced intelligence. The character was created with the same motion-capture technology used to turn Serkis into Peter Jackson's "King Kong" as well as Gollum in the "Lord of the Rings" trilogy. However, the technology remains a sticking point for the Academy, which has always rejected motion-capture-aided performances in the past.

Hammer is a young actor who has done mostly television work in his brief career, including "Veronica Mars," "Gossip Girl," and "Reaper." His breakthrough film role came last year in "The Social Network," in which he played Harvard twins Cameron and Tyler Winklevoss. In "J. Edgar" he plays Clyde Tolson, the lover of J. Edgar Hoover (Leonardo DiCaprio). Director Clint Eastwood has a strong track record with actors, winning Oscars for five of his stars, including three winners in this category (Gene Hackman in "Unforgiven," Tim Robbins in "Mystic River," Morgan Freeman in "Million Dollar Baby").

Foster is a young actor who has already built an impressive resume. He received acclaim for his sinister supporting performance in the western remake "3:10 to Yuma," which earned him a SAG nomination as a member of the ensemble cast. He also starred in the acclaimed film "The Messenger," and though that film earned a nomination for his co-star Woody Harrelson, Foster was not recognized for his work. In "Rampart" he reunited with Harrelson and "Messenger" director Oren Moverman.

Kinglsey is an Oscar favorite, winning Best Actor for "Ghandi" on his first nomination, and he has been nominated three more times: for "Bugsy," "Sexy Beast," and most recently "The House of Sand and Fog." Martin Scorsese has directed numerous actors to Oscar nominations and wins, but "Hugo" is a 3D family film with fantasy elements, and that may not appeal to Oscar voters.

Pitt was originally considered a possible Best Actor contender for "The Tree of Life," in which he plays a disciplinarian suburban father, but the film's diffuse nature (no one actor is given central focus in Terrence Malick's freewheeling metaphysical drama) has prompted a supporting campaign. To date, no actor has ever been nominated for a Terrence Malick film; the director's signature style and vision often overshadows individual performances. But Pitt has a high profile in 2011 (he also appears in the Oscar contender "Moneyball"), and few co-stars to potentially split the vote. If the Academy embraces the film as a whole, Pitt could break through.

For playing the part of an uptight businessman forced to deal with his highstrung wife in the Tony-winning production of Yazmin Reza's play, Jeff Daniels contended for the Best Actor Tony in 2009; he lost to Geoffrey Rush who achieved the triple crown of acting with his win for "Exit the King." That  same year, Waltz took almost every acting prize for his supporting turn in the film "Inglorious Basterds." 

Plummer is a veteran actor whose career spans decades, but nevertheless he has only once been nominated for an Oscar: two years ago for his role as Leo Tolstoy in "The Last Station." In "Beginners" he plays another true-life character: namely the father of writer-director Mike Mills, who came out as gay in his 70s before succumbing to cancer. The Best Supporting Actor category often favors veteran actors, including Martin Landau ("Ed Wood"), James Coburn ("Affliction"), Morgan Freeman ("Million Dollar Baby"), and Alan Arkin ("Little Miss Sunshine"), so Plummer may receive votes not only for this performance but as a de facto career achievement award.

Plummer is a veteran actor who received his only Oscar nomination to date two years ago in this category for "The Last Station." This category often serves as a de facto career achievement award for legendary stars (including Martin Landau, James Coburn, and Alan Arkin), which would give Plummer an edge, but if he is nominated for a Best Supporting Actor Oscar, most consider his performance in "Beginners" to be the much likelier bet.

Firth has become an Oscar favorite in recent years, nominated for Best Actor for "A Single Man" and winning that category last year for "The King's Speech." "Tinker Tailor Soldier Spy" is being touted mostly for the lead performance of Gary Oldman, who has never been nominated for an Oscar, but if voters view the film for Oldman's performance, they might also be inclined to throw their support behind Firth as well.

Stoll gives a brief but scene-stealing performance as author Ernest Hemingway in Woody Allen's "Midnight in Paris." Allen's actors have a strong track record at the Oscars, as do actors playing real people, especially real-life artists. Before appearing in "Midnight," Stoll's greatest claim to fame was a regular role as a detective on NBC's "Law & Order: LA."

Thewlis is a British character actor who has appeared in numerous films, large and small, including "The New World," "Restoration," "The Big Lebowski," and the "Harry Potter" films as Remus Lupin. THis year he appears in "Anonymous" and "The Lady" in addition to "War Horse," which has yet to be seen by critics or audiences. But Spielberg's reputation has already put the film on track for possible Oscar nominations, and Thewlis has never been nominated before. But he may have to compete against other supporting performances in his film from Nicolas Bro and Niels Arestrup ("A Prophet").

Redmayne, who won the Featured Play Actor Tony in 2009 for his performance in "Red," stars opposite Michelle Williams as Marilyn Monroe in this biopic based on the memoir of production assistant Colin Clark. 

Miller is a teenage actor whose work has included recurring roles on "Californication" and "Royal Pains" as well as an appearance in the film "City Island." The lion's share of attention for the drama "We Need to Talk About Kevin" has gone to Tilda Swinton as his mother, but Miller plays the title role and may leave a strong impression on voters; he plays a teenager who perpetrates a school shooting.

In addition to directing "The Ides of March," Clooney also plays a major supporting role as a promising presidential candidate. Clooney won his Oscar in the supporting category, for his work in another ensemble political drama: "Syriana." But this would be the first time for Clooney to direct himself to an Oscar nomination; he had a supporting role in his 2005 directorial debut, "Good Night, and Good Luck," but wasn't nominated. "Ides" has received generally positive reviews, but it's widely believed that his better chance at another Oscar is in the lead race for "The Descendants."

He has never been nominated for an Oscar, but in recent years the ubiquitous character actor has grown in proimence thanks to his performances in the films "Juno," "Burn After Reading," and the "Spider-Man" films. In "The Music Never Stopped" he plays the estranged father of a young man with a debilitation brain tumor, leading them to bond over the son's favorite music. The film was released in March but a screener was sent early to members of the Academy and SAG, and voters sometimes like to award character actors even if their films aren't widely embraced as a whole (Michael Shannon in "Take Shelter," Richard Jenkins in "The Visitor," Stanley Tucci in "The Lovely Bones.")

Irons previously won a Best Actor Oscar for the film "Reversal of Fortune" and appears in the ensemble drama "Margin Call," which chronicles the 2008 financial crisis from inside Wall Street. The film opened to strong reviews, and distributor Roadside Attractions plans to mount an Oscar campaign for the film.

Broadbent plays the husband of Margaret Thatcher in "The Iron Lady." His only previous nomination was for playing another supportive husband ten years ago in "Iris," resulting in a win in this category. However, "The Iron Lady" has not yet been seen by critics or audiences, and the director, stage-vet Phyllida Lloyd, does not have a proven track record at the Oscars; her only previous film was "Mamma Mia!"

As with Waltz, Reilly is stepping into the shoes of a Tony-nominated actor (James Gandolfini) to play the part of a self-made man seeking an apology from the parents of a bully who injured his son. Reilly made Oscar history in 2002 when he appeared in three of the five Best Picture nominees - champ "Chicago," "The Gangs of New York" and "The Hours." He contended for Best Supporting Actor for his performance in "Chicago." 

Goodman is best known for his work on TV, including his Emmy-nominated performance on "Roseanne." On the big screen he has recently contributed voice work to "The Princess and the Frog," "Cars," and "Monsters Inc.," as well as supporting roles in "Speed Racer," "Beyond the Sea," and "O Brother, Where Art Thou?" Though he is a Golden Globe and Emmy winner, he has never been nominated for an Oscar. In "The Artist," which has the potential to sweep the Oscar nominations, he plays a Hollywood studio executive, Al Zimmer.

Hawkes has been working as a character actors for years in film and television, including roles in "Steven Spielberg Presents 'Taken,'" "Deadwood," "American Gangster," and "Me and You and Everyone We Know," but it wasn't until last year's performance as Jennifer Lawrence's fearsome uncle in "Winter's Bone" that he received widespread recognition, including an Oscar nomination in this category. Now officially on Oscar's radar, he returns in another dark indie drama ("Martha Marcy May Marlene") opposite a breakout female star (Elizabeth Olsen). In it he plays another sinister, this time a villainous cult leader.

Hill achieved fame in the Judd Apatow-produced comedy "Superbad" and has since developed a career in similar comedies like "Forgetting Sarah Marshall," "Get Him to the Greek," and "Walk Hard." His performance as a emotionally stunted young man in the dark comedy "Cyrus" was a departure for the actor, and he has received further acclaim for his performance in "Moneyball."

Branagh is a multiple Oscar-nominee, with previous bids for writing, directing, and acting. This would be only his second acting bid, and he has the advantage of playing a real screen legend, Laurence Olivier, in whose footsteps Branagh has followed by adapting works of Shakespeare for the screen. Portraying a screen idol is what helped Cate Blanchett finally secure her elusive first Oscar; she played four-time Oscar champ Katharine Hepburn in "The Aviator."

Spacey is an undefeated two-time Oscar-winner (Best Supporting Actor in "The Usual Suspects" and Best Actor in "American Beauty") and appears in the ensemble drama "Margin Call," which chronicles the 2008 financial crisis from inside Wall Street. The film opened to strong reviews, and distributor Roadside Attractions plans to mount an Oscar campaign for the film.

Like Christopher Plummer, Max von Sydow is another legendary actor who has only been nominated once at the Oscars: for Best Actor in "Pelle the Conqueror." The Swedish actor is famous for his many collaborations with iconic filmmaker Ingmar Bergman and is thought to have a scene-stealing role in "Extremely Loud and Incredibly Close," though the film has not yet been seen by critics or audiences. The director is Stephen Daldry, who has won Oscars for Nicole Kidman ("The Hours") and Kate Winslet ("The Reader") and earned nominations for Julie Walters ("Billy Elliot") and Ed Harris and Julianne Moore ("The Hours").

Nolte is an acting veteran who has been nominated twice for Oscars (for "The Prince of Tides" and "Affliction") despite legal troubles and substance abuse problems. He gives a standout performance in "Warrior," a well-reviewed film in which he plays the father of duelling mixed martial arts fighters, but despite being embraced by critics, the film has underperformed at the box office and is at risk of being forgotten by the time voters get their ballots.

Oswalt is a comic actor known for his performances on TV's "The King of Queens" and "United States of Tara." On film, he voiced Remy in the Oscar-winning animated film "Ratatouille" and proved his dramatic mettle in the black comedy "Big Fan." "Young Adult" is directed by Jason Reitman, a recent favorite of the Academy, who has earned acting nominations for four of his stars.

Since winning Best Actor for 2005's "Capote," Hoffman has been a frequent nominee at the Oscars, earning subsequent bids in this category  for "Charlie Wilson's War" and "Doubt." This year's he gives supporting performances in a pair of awards contenders: "Ides of March," in which he plays a campaign manager for a presidential candidate played by George Clooney, as well as Bennett Miller's "Moneyball."

Forster has been acting for more than forty years, but he didn't receive his first Oscar nomination until he co-starred as a bail bondsman in Quentin Tarantino's "Jackie Brown" (1997). This year he appears in "The Descendants" opposite George Clooney. The film has received excellent reviews on the film festival circuit, and director Alexander Payne has previously earned Oscar acting nominations for Jack Nicholson and Kathy Bates ("About Schmidt"), and Thomas Haden Church and Virginia Madsen ("Sideways").

Tucci is an Emmy-winning character actor who earned his first Oscar nomination for his supporting role as a child-killer in "The Lovely Bones." He appears in the ensemble drama "Margin Call," which chronicles the 2008 financial crisis from inside Wall Street. The film opened to strong reviews, and distributor Roadside Attractions plans to mount an Oscar campaign for the film.

Skarsgard is a veteran of Swedish and American film and television, including roles in Oscar-contenders "Good Will Hunting," "Breaking the Waves," and "The Unbearable Lightness of Being," but he has never been nominated for an Oscar. In "The Girl with the Dragon Tattoo" he plays a member of a powerful family that is the subject of a murder investigation. He also appears this year in Lars von Trier's film "Melancholia."

Hanks is a beloved figure in Hollywood. He has won two Best Actor Oscars ("Phildelphia," "Forrest Gump") out of five nominations, and in "Extremely Loud and Incredibly Close" he plays a father who dies on 9/11. The film is directed by Stephen Daldry, who in only three previous films has already directed five actors to Oscar nominations. However, advance buzz indicates that Hanks's co-star Max von Sydow may be the film's stronger candidate for a Best Supporting Actor nomination, which might draw votes away from Hanks.

Oscar loves actors playing real characters, which helps Mortensen, who plays the famous and controversial psychologist Sigmund Freud in "A Dangerous Method." Also possibly helping him is the fact that this is his third collaboration with director David Cronenberg; their last film together, "Eastern Promises," earned Mortensen his first and, to date, only Oscar bid.