1 of 20
Adam Driver, Girls
The big break: Most of us first met Adam Driver as the Girls character who shares his name. And while it was initially strange to see Driver play something other than a weirdo hipster—his appearance in 2012's Lincoln was especially disorienting—supporting roles in the likes of Frances Ha and Inside Llewyn Davis soon proved his versatility. Clearly J.J. Abrams saw something too: in 2014, the director cast Driver in Star Wars: The Force Awakens.
Did he stay or did he go? Driver's still a regular on Girls, which has been renewed for a fifth season—though depending on the status of Adam and Hannah's relationship, the series could easily go on without Driver. And either way, Star Wars should propel him to wider name recognition, while a role in Martin Scorsese's Silence should up his prestige cred. It won't be difficult for Driver to leave Brooklyn (and ''Adam'') behind. —Esther Zuckerman
2 of 20
Katherine Heigl, Grey's Anatomy
The big break: Heigl started on Grey's as a member of the original cast in 2005, and two years later began a run of feature-length rom-coms with Judd Apatow's raunchy Knocked Up. Although her film performances weren't particularly acclaimed, she did nab an Emmy in 2007 for playing the troubled Izzie on Grey's.
Did she stay or did she go? Heigl left Grey's six seasons in to, as she said, spend more time with family. This departure came with a lot of drama—Heigl was vocal about her disdain for her character's recent arcs—and was followed by Heigl doing more undistinguished film work before returning to TV. She now stars on NBC's successful drama State of Affairs. —Ariana Bacle
3 of 20
Shelley Long, Cheers
The big break: Long is still best known for playing Diane Chambers on NBC's classic sitcom—and specifically, as half of one of television's best-loved will-they/won't-they couples, along with Ted Danson's Sam. She won tons of acclaim for her work on the show, including two Golden Globes and an Emmy.
Did she stay or did she go? Cheers was still at the height of its popularity when Long made the controversial decision to leave the series in 1987 so that she could pursue more film work. That decision cost her dearly: Long's big screen output (Troop Beverly Hills, a few Brady Bunch movies) was modest, to say the least, while Cheers continued to thrive through its series finale in 1993. (Long did stop by for the closer, and later played Diane again on the spinoff Frasier.) Unfortunately, Long didn't do much of note after leaving the place where everybody knew her name. —Samantha Highfill
4 of 20
George Clooney, ER
The big break: After a slew of middling television roles, Clooney made it big in his role as Doug Ross on ER. During that time, Clooney's popularity led him to star in films such as From Dusk Till Dawn, One Fine Day, and the unforgettable and kind of regrettable Batman & Robin.
Did he stay or did he go? Clooney left the show in its fifth season to focus on his rising film career—and what a career it has been. Clooney went on to star in several acclaimed films, winning the Best Aupporting Actor Oscar for Syriana, and a Best Picture Oscar as a producer of Argo alongside Ben Affleck and Grant Heslov. —Teresa Jue
5 of 20
Eddie Murphy, Saturday Night Live
The big break: Murphy became the sketch show's breakout star in its otherwise disastrous sixth season. Murphy's star quotient rose further during his run on SNL when he starred in 48 Hours; in 1982, he even made history by becoming the first (and still only) person to host the series while still a member of its cast.
Did he stay or did he go? Murphy left the show in 1984, and soon cemented himself as a bona fide film star—even if some of those films have been less than critically-acclaimed. Murphy's feelings about SNL are sour at best, especially since the show made a dig about Murphy being a ''falling star'' in the early '90s. —Teresa Jue
6 of 20
David Duchovny, The X-Files
The big break: Duchovny became a cult TV sex symbol when he began starring on Chris Carter's paranoid sci-fi drama in 1993, inspiring scores of fan fiction and at least one quasi-hit song (Bree Sharp's ''David Duchovny'').
Did he stay or did he go? Contract disputes plagued the end of Duchovny's run as Agent Fox Mulder, when Duchovny won $20 million in a lawsuit against 20th Century Fox over being underpaid for TV rights sales. Duchovny said at the time that he did not want to do the show anymore, ''creatively or professionally.'' He quit full-time in season seven, eventually agreeing to return for 12 episodes in season eight. After X, Duchovny turned to cable to reinvent his career in Showtime?s Californication; the series ended up running for seven seasons. —Teresa Jue
7 of 20
Suzanne Somers, Three's Company
The big break: As ditzy blonde Chrissy, Somers became known for her comic timing and, uh, her other...assets. A 1980 Playboy spread (of old photos taken when Somers was a struggling young model) helped fan the flames.
Did she stay or did she go? By 1981, Somers wanted more money to continue with Three's Company. Instead, the show got rid of her character before ultimately ending in 1984. Somers' career took time to recover; in the late 1980's, she returned to TV in She's the Sheriff before landing her next big role on Step by Step in 1991. —Samantha Highfill
8 of 20
Donald Glover, Community
The big break: Comedy fans already knew Glover's name from his work as a writer on 30 Rock, but it was his role as Community's lovable jock Troy Barnes that shot him to fame. Proving to be a triple threat, Glover also released two studio rap albums under the name Childish Gambino during Community's run and shot a buzzy guest spot on HBO's Girls in 2013.
Did he stay or did he go? Glover left Community midway through its fifth season. In a series of Instagram messages, he declared that the decision was not due to his rap career, adding that he ''wanted to be on [his] own.'' He also signed on to create and star in a music-themed comedy, Atlanta, for FX. The network recently ordered a pilot, so it seems a return to television might be in his future. —Kelly Connolly
9 of 20
Steve Carell, The Office
The big break: The Office made Steve Carell a household name—and got the comedic actor a lot more film work: During his time on the show, he starred in multiple movies including Little Miss Sunshine, Get Smart, and Dinner for Schmucks. All the while, he continued to earn Emmy and Golden Globes nods for his Office role.
Did he stay or did he go? Carell left The Office in 2011 to focus more on film. And he's made several movies since, though none have caught on the way his Office-era films did—save his recent dramatic turn in 2014's Foxcatcher. —Ariana Bacle
10 of 20
David Caruso, NYPD Blue
The big break: Caruso snagged a Golden Globe in 1993 for playing the gritty cop drama's lead role, the brilliant detective John Kelly; the series' critical acclaim and healthy ratings meant that it and Caruso were on an upward trajectory together.
Did he stay or did he go? Well, at least until season 2, when Caruso publically (and contentiously) left the series, citing both producers' failure to give him the raise he wanted and a desire to make movies. The move turned out to be a major misstep; Caruso couldn't find his foothold in film and eventually returned to TV as CSI: Miami's shade-happy Lieutenant Horatio Caine. Looks like in the '90s, David could have used some—puts on sunglasses—Caruso-control. Yaaaaaah! —Hillary Busis
11 of 20
Ashton Kutcher, That '70s Show
The big break: Kutcher was an unknown 20-year-old actor/model when Fox's retro comedy debuted in 1998 and quickly became one of the network's flagship shows. He soon broke out as the show's major heartthrob—and became known for his work outside the '70s when he created and starred in MTV's hidden camera prank show Punk'd in 2003. (Also, Dude, Where's My Car?)
Did he stay or did he go? Kutcher was happy to stick around the past for seven seasons, but he left the series in 2004 (one year before it concluded) to focus on making features, producing reality shows, and investing in a series of high-profile tech properties (including Skype and Airbnb). He's currently earning about a bajillion dollars per episode on CBS's Two and a Half Men. —Hillary Busis
12 of 20
Dan Stevens, Downton Abbey
The big break: As Matthew Crawley, Dan Stevens won over the cold heart of Lady Mary and the warmer hearts of Downton viewers.
Did he stay or did he go? Cousin Matthew, however, was not long for this world, and was killed off when Stevens opted to leave the show to pursue bigger and better things. And though Downton arguably isn't what it used to be, Stevens' bet hasn't yet totally paid off with a major role in a major movie. Perhaps the best indication of Stevens's star quality is 2014's The Guest, a thriller which seems destined for cult status. —Esther Zuckerman
13 of 20
John Travolta, Welcome Back Kotter
The big break: John Travolta's fame swelled during his run as Vinnie Barbarino, thanks to starring roles in two seminal '70s features: Saturday Night Fever and Grease.
Did he stay or did he go? Travolta stuck with the series for four seasons (though he was billed as a ''special guest star'' during the last one), then left to live career highs in the '70s, the lows in the '80s and early '90s, and a revival in the '90s, thanks to pulp fiction Pulp Fiction. And another comeback is in the works: Travolta is finally returning to TV this year, where he will take on the role of Robert Shapiro in Ryan Murphy's O.J. Simpson FX miniseries, American Crime Story. —Teresa Jue
14 of 20
Jason Segel, How I Met Your Mother
The big break: How I Met Your Mother began in 2005, and by 2008, Jason Segel was starring in the well-received Forgetting Sarah Marshall. By the series' end, Segel had multiple comedies under his belt—including 2009's I Love You, Man and 2011's The Muppets—and to this day is more known for those than for his work on the TV show.
Did he stay or did he go? Segel was able to maintain a successful film career while starring on HIMYM until the show ended in 2014, and has since starred in Sex Tape—a comedy that was not well-received in critical circles, but did make some cash. He's currently working on a film about writer David Foster Wallace. In other words? He's doing just fine. —Ariana Bacle
15 of 20
Zach Braff, Scrubs
The big break: Braff showed off his goofy charm on Scrubs starting in 2001, but in 2004 it looked like he was poised to make it big as a multi-hyphenate filmmaker, thanks to the critical success of Garden State.
Did he stay or did he go? Braff stuck with Scrubs through most of its long run, though he did pursue a few more film roles along the way (The Last Kiss, anyone?). His 2014 Garden State follow-up as a director, Wish I Was Here, was not as beloved. —Esther Zuckerman
16 of 20
Chris Pratt, Parks and Recreation
The big break: Pratt broke out in his role as the loveable doofus Andy Dwyer while steadily building his film career, taking on supporting roles in prestige films like Moneyball, Zero Dark Thirty, and Her. Pratt ultimately took the leading man reins when he starred in 2014's summer blockbuster Guardians of the Galaxy. (Parks explained Pratt's absence due to filming by sending Andy off to London for a few months.)
Did he stay or did he go? Season 7 is the series' last, so Pratt, along with the rest of the Parks and Recreation cast, will all be leaving Pawnee this year. Pratt's probably the hottest Chris around these days, so his star quotient is in no danger of falling once the show ends; he'll soon helm another franchise, Jurassic World. —Teresa Jue
17 of 20
Michael J. Fox, Family Ties
The big break: Fox won the role of Alex P. Keaton reportedly only because Matthew Broderick had turned it down—but he proved to be anything but a second choice on the NBC sitcom, winning three consecutive Best Actor Emmys in 1986, 1987, and 1988. In the meantime, Fox built up his film resume with roles in Teen Wolf, The Secret of My Success, and, of course, Back to the Future, 1985's highest-grossing movie.
Did he stay or did he go? Despite his rising star, Fox stayed loyal to his TV Family for each of the show's seven seasons; he followed it with a series of moderately successful films before returning to television a second time via ABC's Spin City. It was a success; his much-ballyhooed third return to the small screen, on NBC's The Michael J. Fox Show, alas, was not. —Hillary Busis
18 of 20
Chevy Chase, Saturday Night Live
The big break: Though the entire first cast of SNL is now legendary, it was Chase who was the show's very first breakout star. See, for instance, the song the women of the cast performed imitating the fervor for him. (Off screen, however, Chase was reportedly not beloved by his fellow cast members.)
Did he stay or did he go? Chase left the show after a single season, but has said he did so because of his relationship with ''a girl that I was in love with''—not ''lucrative film deals awaiting me.'' Though Caddyshack didn't come until a couple of years later, ultimately Chase's decision was anything but a career ender. —Esther Zuckerman
19 of 20
Blake Lively, Gossip Girl
The big break: Blake Lively starred in teen favorite The Sisterhood of the Traveling Pants in 2005, but her break really came when she began starring on Gossip Girl in 2007. Although she didn't appear in many films during her time on the drama, she quickly became the show's stand-out thanks to her willingness to venture—however little—into the movie world, which the rest of the cast didn't really do.
Did she stay or did she go? Lively stuck around as Serena van der Woodsen until the series' very end, but started ducking out of the acting world after the show's 2012's conclusion in favor of working on a Goop-like lifestyle brand, Preserve, that launched this year. —Ariana Bacle
20 of 20
Melissa McCarthy, Mike and Molly
The big break: Although Gilmore Girls fans had known McCarthy for years, she didn't get a starring role on TV until the CBS sitcom launched in 2010—and it wasn't until 2011's Bridesmaids that she became a household name. (She also snagged an Emmy that fall; though the award was technically for Molly, it's tough to imagine the film's popularity had nothing to do with her win.) From there, her list of comedy credentials has grown to include The Heat, Tammy, and more.
Did she stay or did she go? Despite a growing film career, McCarthy has remained attached to Mike and Molly. She's been making things work for a few years now, so unless there's a big change in her schedule, we suspect she'll stick around. —Samantha Highfill