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LEIGHTON MEESTER & ED WESTWICK ON GOSSIP GIRL
The show's creators called Meester's Blair Waldorf and Westwick's Chuck Bass the king and queen at the center of the Gossip Girl . In the twisted web of the Upper East Side soap opera, Meester and Westwick are so good at being bad that fans can't get enough. And while waiting to see what dirty plan they'll hatch next, you want for Blair and Chuck to get back together just to see their chemistry in action.
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MICHAEL URIE & BECKI NEWTON ON UGLY BETTY
Urie and Newton play off each other with campy glee as Betty's (America Ferrera) tormentors Marc St. James and Amanda Tanen. Whether whooping it up, pom-poms and all, as Mode's flamboyant cheerleading squad of two ("You're Elle, you smell, your team can go to hell!") or going head-to-head with guest star Lindsay Lohan, they're a laugh-out-loud duo you wouldn't want to cross.
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BROOKE SMITH ON GREY'S ANATOMY
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MICHAEL EMERSON ON LOST
As the menacing Benjamin Linus on Lost, two-time Emmy nominee Emerson (right, with Terry O'Quinn) pulled the puppet strings as the ringleader of "The Others" with a steely-eyed menace – and continued to be compelling even after his character was captured. Is Ben feeding the survivors of Oceanic Flight 815 misinformation or trying to help them? Emerson kept you on the edge of your seat guessing.
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DANA DELANEY ON DESPERATE HOUSEWIVES
Delaney's mysterious Katherine Mayfair moved to Wisteria Lane and instantly became the neighbor whose secrets we most wanted to learn. And even as Katherine's icy exterior melted, and her feud with fellow Martha Stewart wannabe Bree Van de Kamp (Marcia Cross, pictured) ended, Delaney managed to still make her intriguing. Look no further than Katherine's videotaped sex-capade with James Denton's Mike Delfino.
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JEAN SMART ON SAMANTHA WHO?
Playing Christina Applegate's manipulative mother Regina Newly on Samantha Who?, Emmy winner Jean Smart consistently delivered her lines with a razor-sharp edge. A classic moment: telling Samantha and her pal Dena (Melissa McCarthy) that making s'mores when they were growing up wasn't about being maternal. "I only made them so the two of you could have fun together playing with fire while I finished the crossword," she crowed.
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RAINN WILSON ON THE OFFICE
Mercy-killing a cat by putting it in the freezer and simulating childbirth using a watermelon are just two of Rainn Wilson's most twisted moments as Dwight K. Schrute on The Office. And as insane as he can play him, Wilson is also skilled at letting the rare emotional side of the beet farmer peek through, like his sobbing scene in the stairwell after Angela (played by Angela Kinsey, pictured) breaks up with him. Making viewers feel for Dwight? That's no easy feat.
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JESSICA WALTER ON 90210
All eyes are on Jessica Walter (right, with Shenae Grimes, Rob Estes and Lori Loughlin) when she's in a scene as family matriarch Tabitha Wilson on 90210. While directing granddaughter Annie's (Grimes) West Beverly Hills High production of Spring Awakening, she had a tirade of Joan Crawford proportions. "You've got to sing like your privates are on fire!" Walter yelled – and then showed them how it's done.
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JACK MCBRAYER ON 30 ROCK
His aw-shucks portrayal of naïve NBC page Kenneth Parcell on 30 Rock makes Jack McBrayer the perfect foil for costars Tina Fey and Alec Baldwin. And the comedian (left, with Judah Friedlander and Tracy Morgan) is at his finest when he can run wild with Kenneth, like when he tried cappuccino for the first time and developed a full-blown addiction. A caffeine bender was never so funny.
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