What Richard Did Jack Reynor
Jack Reynor
If you're the kind of person who pays attention to casting announcements and that sort of thing, there's a name that you'll have spotted popping up a lot in the last few months of 2012, an Irish kid barely out of his teens who suddenly seemed to be linked to every part for a young actor in Hollywood, before landing one of the biggest ones going: the male lead, alongside Mark Wahlberg, in "Transformers 4." What's even more remarkable, given the quality of that franchise so far, is that Jack Reynor is the real deal. The 21-year-old was actually born in Colorado, but moved back to Ireland when he was two. He started acting properly in his late teens, picking up his first movie role in Kristen Sheridan's bleak, hedonistic "Dollhouse," which was one of the better surprises of our time in Berlin in 2012. But it was later last year that Reynor truly impressed. He has the title role in Lenny Abrahamson's searing contemporary drama "What Richard Did," as a confident, wealthy Irish boy who after falling for a local girl, becomes embroiled in an accidental killing, one that his community refuses to let him take the fall for. It's an incredibly charismatic, and powerful turn (which U.S audience will be able to see later in the year, after it screens at Tribeca next month), and it's no surprise that Hollywood came calling: first with a key role in Vince Vaughn comedy "The Delivery Man," then tests for the male led in young adult property "Divergent," then the part in "Transformers 4," in which he'll play the racecar driving boyfriend to the daughter of Mark Wahlberg's character. And from there, the world's pretty much his oyster.

Downton Abbey Dan Stevens
Dan Stevens
The show only becomes a bigger hit even as it gets progressively worse, but we're still yet to see a graduate of the show truly blow up to become a movie star (excluding Maggie Smith, of course...). Several cast members are getting there: Jessica Brown-Findlay, one of our picks from last year, has a lead alongside Colin Farrell, Russell Crowe and Will Smith in "Winter's Tale," and Michelle Dockery's setting up some diverse credits, from "Anna Karenina" to Liam Neeson thriller "Non-Stop." But it's distinctly possible that the first true big-screen breakout from the show will be Dan Stevens, who played Cousin Matthew on 'Downton.' The 30-year-old Stevens is a Cambridge graduate who got his big break after plaing Macbeth to Rebecca Hall's Lady Macbeth while still at the university. Hall's father, theater director Peter Hall, then went on to cast Stevens in a production of "As You Like It." This then saw Stevens win the main part in the BBC TV version of Alan Hollinghurst's "The Line of Beauty" (which also introduced the world to Hayley Atwell), which led to further TV gigs, most notably in the most recent version of "Sense & Sensibility." But it was repressed, responsible heartthrob Matthew Crawley that made him a household name, and pin-up both in the U.K. and abroad. But his ambitions clearly stretched beyond Downton: he executive-produced and starred in the upcoming period romance "Summer In February" co-starring Dominic Cooper and Emily Browning (the film opens in June in the UK), and *SPOILER* arranged to be killed off at the end of the third season of 'Downton' in order to pursue more Hollywood roles. Right now, his U.S. gigs run to a part in Amy Heckerling's horror-comedy "Vamps," but there's some big projects on the way. He's playing Guardian reporter Ian Katz in Wikileaks drama "The Fifth Estate," alongside Benedict Cumberbatch, and will segue to something very different soon after -- Scott Frank's pitch-black neo-noir "A Walk Among The Tombstones," opposite Liam Neeson and Ruth Wilson. If the film works out, it's a potential revelation, and could lead to all kinds of new opportunities.

Corey Stoll House of Cards
Corey Stoll
Of all the fine performances in "House of Cards," there's one that stands out in particular, from an actor who, while not yet a household name, was building on a memorable big-screen breakout, and looks to move onwards and upwards from here on out. Corey Stoll, who plays Congressman Peter Russo on the show, is a Tisch graduate, who initially made his name on stage, picking up a Drama Desk Award nomination opposite Viola Davis in "Intimate Apparel" in 2004. Some small movie roles followed, including in "North Country," "Lucky Number Slevin" and "Salt," and Stoll bagged a regular role on short-lived procedural "Law & Order: LA," proving a highlight even among more storied colleagues like Alfred Molina and Terrence Howard. But it was in 2011 that Stoll truly impressed, as Ernest Hemingway in Woody Allen's "Midnight In Paris." Bigger names have taken on the famed author, but Stoll's turn is probably the definitive screen Hemingway at this point, and it was done with only a minimum of screen time. The film landed him a small, somewhat thankless part in "The Bourne Legacy," but the start of this year saw him fulfill his potential as the barely-on-the-wagon Congressman who finds himself appointed the protege to Kevin Spacey's Frank Underwood. It'll surely lead to an Emmy nomination, if there's any justice at least, and while he' s been courted for other TV roles since the success of 'Cards,' he seems to be keen to push things forward in the movies. He has indie boxing noir "Glass Jar," biopic "Decoding Annie Parker," and Liam Neeson actioner "Non-Stop" lined up, and just joined the cast of comedy-drama "This Is Where I Leave You," with Jason Bateman, Tina Fey and Jane Fonda.

Omar Sy
Omar Sy
The most successful film of last year that you probably didn't see (it took $426 million worldwide, outgrossing "Prometheus," "Snow White & The Huntsman" and "Django Unchained"), the Oscar-nominated "The Intouchables" achieved many things, but among them is breaking out French comedy star Omar Sy onto the world stage. The 35-year-old, born in France to a Senegalese father and a Mauritian mother, first came to attention at home as part of comedy duo Omar et Fred, with Fred Testot, who host a regular segment on the popular "Le Grand Journal" news show. And soon, Sy broke into movies, with 2006's "Nos jours heureux," and more notably, in Jean-Pierre Jeunet's 2009 comedy "MicMacs," in which he impressed in a supporting role as the ethnographer pal of Dany Boon's lead. But it was "The Intouchables," released in France two years later, that turned him into a superstar in much of the rest of the world (even if the film was only a modest arthouse hit stateside). His performance as Driss, the aimless ex-con who discovers a new lease on life by becoming the caretaker, and friend, of wealthy quadriplegic Philippe (Francois Cluzet) was charming, funny and showed he had dramatic chops as well. He should get further exposure with a supporting role in Michel Gondry's promising "Mood Indigo," and a U.S. breakthrough seems to be certainly close -- he'll join one of the bigger superhero franchises out there, as a new addition to "X-Men: Days Of Future Past," and also has a team-up with Bradley Cooper on "Chef" brewing as well.

Honorable Mentions: We wanted to go with some fresher faces for this piece, which is why actors like Jason Clarke, Chris Pratt (who we included in a TV on the rise piece last year) Charlie Hunnam, Eddie Redmayne and Daniel Bruhl, who've all landed big gigs of late, didn't quite make the cut simply because they're well established in comparison. And some other names to keep an eye out for include: Sam Reid, who features in the upcoming "Belle" and "Serena"; Tom Holland, who broke out in "The Impossible"; "The Walking Dead" actor Jon Berthal, who'll next be seen in "The Wolf Of Wall Street" and Frank Darabont's upcoming noir series; Chadwick Boseman, who plays Jackie Robinson in "42"; "The Killing" actor Liam James, who has the lead in Sundance hit "The Way Way Back"; charismatic British actor Jack O'Connell, who makes his blockbuster debut this summer with "300: Rise Of An Empire"; rising Aussie star Brenton Thwaites, who has a big part in "Maleficent" and "Headhunters" actor Askel Hennie, who recently joined Dwayne Johnson in "Hercules." We also didn't want to include those we highlighted in our recent Sundance breakouts piece, including "Fruitvale" actor Michael B. Jordan.

-Oliver Lyttleton, Kevin Jagernauth, Rodrigo Perez