1 of 15 David James/HBO; AMC
James Badge Dale, The Pacific and Rubicon
Prior to this year, we knew Dale best as the guy who got his hand chopped off by Jack Bauer in the third season of 24. But this year, he showed viewers he could do grueling intensity as a Marine in HBO's war drama The Pacific and brainy as a think tank analyst on AMC's short-lived political thriller Rubicon.
2 of 15 Columbia Pictures
Jesse Eisenberg, The Social Network
Think what you will of Mark Zuckerberg, Eisenberg's portrayal of the polarizing founder of Facebook made him out to be not just a blowhard, but a lonely, mildly sympathetic one. (That's an achievement!)
3 of 15 Adam Taylor/NBC
Jason Ritter, The Event
It's understandable if you missed Ritter's fine work as a paraplegic in Joan of Arcadia or as nice guy pediatrician Ethan on the CBS short-lived sitcom The Class. But there's no missing him in NBC's sci-fi mystery The Event, in which he plays bewildered everyman Sean Walker. It could have been a frustratingly hokey part, but in Ritter's hands it veers into interesting: a little hysterical and deliciously paranoid.
4 of 15 Danny Feld/ABC
Jake Lacy, Better with You
The show isn't perfect, but it's worth watching for Lacy's performance as lovable doofus Casey alone. The perfect mix of heart and dim-witted humor, he's one catchphrase away from being this decade's Joey Tribbiani.
5 of 15 Ben Mark Holzberg/The CW
Maggie Q, Nikita
A bonafide star in Asian cinema who was hand-picked years ago by Jackie Chan to train as one of Hong Kong's budding action heroes, Q has the seductive self-assurance of an Angelina Jolie in the making. In Nikita, she plays a former assassin out for revenge, taking down the bad guys poolside or over cocktails with steely-yet-sultry resolve.
6 of 15 John P. Johnson/HBO
Joe Manganiello, True Blood
Sookie's got fatal problems, yes, but if they look like Bill, Eric and most recent sort-of suitor Alcide, then bring it on! Manganiello's intensely loyal werewolf was an instant hit with fans, too: He was promoted to series regular half-way through the season.
7 of 15 Columbia Pictures
Andrew Garfield, The Social Network and Never Let Me Go
Garfield made headlines that caused many to scratch their heads and ask "Who?" when he was cast as the lead of the new Spider-Man reboot, due out in 2012. But that was earlier this year, and since then, he's already made two star turns: He was an eager cheerleader-turned-screwed-over friend in The Social Network and gave a wrenching portrayal of an organ donor in Never Let Me Go. No doubt Peter Parker will be just as smashing.
8 of 15 Abbot Genser/HBO
Kelly MacDonald, Boardwalk Empire
The Scottish actress has taken on only the meatiest, most memorable of supporting film roles, among them a junkie in Trainspotting, a maid in the manor murder mystery Gosford Park, and the wife of the ill-fated Llewelyn Moss in No Country for Old Men. But on Boardwalk Empire, the rags-to- riches story of her conflicted Irish widower Margaret Schroeder has MacDonald finally sharing the spotlight. Her discovery that it was Nucky who killed her abusive husband? Emmy shivers.
9 of 15 TWD Productions/AMC
Andrew Lincoln, The Walking Dead
The ladies will recall Lincoln as the victim of unrequited love in Love, Actually — he showed up with that silent declaration of love for Kiera Knightly's character at the end. He's traded in the sap for flesh-eating gore in AMC's zombie drama The Walking Dead, on which he plays the unofficial leader of a group of survivors outside of Atlanta. In a world overtaken by the undead, Lincoln helps ground the horror in gritty realism.
10 of 15 Screen Gems
Emma Stone, Easy A
Stone's sly performance as a charming liar in the high school romp Easy A reminded of us Lindsay Lohan's sharper days. She's funny and whip smart. Color us dazzled.
11 of 15 Walt Disney Pictures; Focus Features
Mia Wasikowska, Alice in Wonderland and The Kids Are All Right
Still recovering from watching Wasikowska's gutting performance as a broken teen on HBO's In Treatment? You're not alone. Fortunately, the Australian actress' less intense roles — Alice in Tim Burton's update of Alice in Wonderland and college-bound Joni in The Kids Are All Right — are no less mesmerizing.
12 of 15 AMC
Jessica Paré, Mad Men
Let's get one thing straight: Megan is not Betty 2.0. Gorgeous and smitten as all of Don's paramours have been, Paré's office secretary-turned-the next Mrs. Don Draper is singularly gentle, good with kids and genuinely interested in the world around her. She challenges Don just enough (as opposed to Faye, who perhaps knew too much.) Her shock when Don popped the question in the season finale mirrored our own, but we're more than happy to have Paré stick around as Betty's intriguing alternative.
13 of 15 Columbia Pictures
Rooney Mara, The Social Network
With an assist from Social Network screenwriter Aaron Sorkin, Mara packed an ego-bruising punch as Mark Zuckerberg's ex-girlfriend in just a couple of scenes. Hers was a kiss-off that won't soon be forgotten: "You're going to be successful, and rich," she tells Zuckerberg. "But you're going to go through life thinking that girls don't like you because you're a geek. And I want you to know, from the bottom of my heart, that that won't be true. It'll be because you're an ass----." Next up, she'll take on punk as The Girl with the Dragon Tattoo's Lisbeth Salander.
14 of 15 Jordin Althaus/Showtime
Alexander Gould, Weeds
It's hard to believe that Gould first popped up on our radar as the voice of lost little Nemo in Pixar's Finding Nemo. My how he's grown. As Shane, he has grown from the Botwins' pint-sized moral compass to a teen who has murdered to protect his family. It's transformed him into a bit of a sociopath, a killer without — or with very little — remorse. Gould pulls it off without making Shane, well, too creepy.
15 of 15 Abbot Genser/HBO
Paz De La Huerta, Boardwalk Empire
We'll say one thing for de la Huerta: She isn't shy. As randy showgirl Lucy Danziger, the 26-year-old actress and former model has held her own against Boardwalk Empire's formidable cast — and not just with the full-frontal nudity. How? In a world of deeply flawed crooks and gangsters using physical force to get what they want, she plays a woman who, however irritable, more or less does the same.