1 of 22 Michael Parmelee/NBC
Katherine Heigl, State of Affairs
How you know her: The notoriously outspoken actress starred in My Father the Hero and Roswell and hit the big time as Izzie on Grey's Anatomy. She won an Emmy for Grey's in 2007, the same year she starred in Knocked Up, which led to one rom-com too many. She negotiated out of her Grey's contract in 2010.
The New Role: Heigl trades in her stethoscope for classified case files as CIA analyst Charleston Tucker (yes, that is her name), who advises the president (Alfre Woodard) and who was once engaged to POTUS' now-dead son. What's the hardest part of the show for her? "Mostly just trying to get people to believe I could be a CIA analyst," she quipped.
2 of 22 Nicole Rivelli/ABC
Viola Davis, How to Get Away with Murder
How you know her: A two-time Tony winner, Davis co-starred in Antwone Fisher, Far From Heaven and Steven Soderbergh's films Out of Sight, Traffic and Solaris before breaking through with her Oscar-nominated, snot-filled, one-scene spectacle in Doubt. She earned her second Oscar nod for The Help. Her TV credits include Law & Order: SVU, United States of Tara and the short-lived ABC thriller Traveler with Matt Bomer.
The New Role: Murder, she taught! Davis stars as Annalise Keating, a brilliant, imposing law professor who challenges her students with real cases, only for them to end up entangled in an actual murder plot. Naturally, Annalise has some dirty little secrets of her own.
3 of 22 KC Bailey/NBC
Debra Messing, The Mysteries of Laura
How you know her: Messing won an Emmy as the lovably neurotic Grace Adler on Will & Grace and then raided a scarf factory on Smash.
The New Role: As the titular character, Messing is a successful homicide detective trying to juggle her personal life, which includes an ex-husband and a devilish set of twin boys. Hey, they can't be as bad as Leo.
4 of 22 Richard Cartwright/CBS
Maggie Q and Dylan McDermott, Stalker
How you know them: Q kicked ass as the titular Nikita for four seasons. McDermott won a Golden Globe for The Practice before starring on the first two seasons of American Horror Story (where he did this). Last season, he starred on the DOA Hostages.
The New Role: Q is Beth Davis, the no-nonsense head of the LAPD's Threat Assessment Unit, which investigates stalking cases. McDermott is her new partner, Jack Larsen, who doesn't quite leave his past behind when he transfers and totally gets things off on the wrong foot with Beth.
5 of 22 Jessica Miglio/FOX
Ben McKenzie, Gotham
How you know him: After Peter Gallagher saved him from the rough-and-tumble streets of Chino on The O.C., McKenzie joined the force on Southland.
The New Role: Welcome to Gotham, bitch! McKenzie will retain a police badge for the Batman prequel, playing a young James Gordon, an idealistic detective and war hero who vows to clean up the streets of Gotham.
6 of 22 John Fleenon/NBC
Kate Walsh, Bad Judge
How you know her: As Addison Montgomery, Walsh was the third wheel in MerDer's love story on Grey's Anatomy before starring on the spin-off Private Practice. She most recently played foul-mouthed ex-stripper Gina Hess on Fargo.
The New Role: All rise for Rebecca Wright! Walsh's party animal judge is as ruthless in the courtroom as she is reckless in her personal life. We're talking booze, sex and her band dubbed Ladycock.
7 of 22 Adam Taylor
Anthony Anderson, Black-ish
How you know him: After starring on his own sitcom All About the Andersons and The Bernie Mac Show, Anderson played Det. Kevin Bernard on the last three seasons of Law & Order.
The New Role: Anderson plays Andre "Dre" Johnson, an upper-middle-class family man who's struggling to raise his kids with a sense of cultural identity. Hence, the bro mitzvah he throws in the pilot.
8 of 22 Ed Araquel/FOX
Anna Gunn, Gracepoint
How you know her: Gunn won an Emmy (and possibly will have won her second by the time Gracepoint premieres) for her career-defining role as Skyler White on Breaking Bad.
The New Role: Unlike Skyler, Gunn's Det. Ellie Miller is a happily married mother on the stateside Broadchurch adaptation. But she loses out on a promised promotion to outsider Det. Emmett Carver (David Tennant), with whom she teams to solve a boy's murder in her sleepy hometown.
9 of 22 Skip Bolen/CBS
Scott Bakula, NCIS: New Orleans
How you know him: Bakula won a Golden Globe for time-traveling on Quantum Leap, captained the Enterprise on Star Trek: Enterprise and struggled with middle age on Men of a Certain Age. He has also appeared on Chuck (as Chuck's dad) and is currently recurring on Looking.
The New Role: Bakula heads to the Big Easy as agent Dwayne Cassius Pride, one of the survivors of the Fed. Five and a close friend of Gibbs'. Unlike his old pal, Pride doesn't keep things close to the vest, but his underlings do have to call him "King." Can't make this up!
10 of 22 Alex Martinez/FOX
Octavia Spencer, Red Band Society
How you know her: After co-starring roles and bit parts on the big and small screens, Spencer won a Golden Globe, a Screen Actors Guild Award and an Oscar for The Help. She earned raves for Fruitvale Station last year and can currently be seen in Get On Up, which also features her Help co-star and How to Get Away with Murder's Viola Davis. Her recent TV credits include 30 Rock and a recurring role on Mom.
The New Role: Spencer — who would've been the new Jessica Fletcher had things turned out a bit differently — plays the tough-loving Nurse Jackson, who oversees the pediatrics ward of a hospital.
11 of 22 David M. Russell/CBS
Tea Leoni and Tim Daly, Madam Secretary
12 of 22 Colleen Hayes/NBC
Casey Wilson, Marry Me
How you know her: The Saturday Night Live alum was a-mah-zing on Happy Endings, what with Penny's abreevs and everything. She's also spoofing your favorite Real Housewives on Hulu's The Hotwives of Orlando.
The New Role: Wilson plays Annie to Ken Marino's Jake, a longtime couple who finally gets engaged after a couple of proposals gone awry. The series is based on Wilson's relationship with her husband, show creator David Caspe, who also created Happy Endings.
13 of 22 Jack Rowand/The CW
Jesse L. Martin, The Flash
How you know him: Martin played Det. Ed Green on Law & Order for nine seasons, primarily partnering with Lennie Briscoe. He also originated the role of Tom Collins in the stage production and subsequent film adaptation of Rent and most recently recurred on Smash.
The New Role: He's still a cop! Martin plays Joe West, a blue-collar detective and surrogate father to Barry Allen (Grant Gustin). Joe also has a daughter, Iris (Candice Patton), Barry's BFF and love interest.
14 of 22 Monthy Brinton/CBS
Laurie Metcalf, The McCarthys
How you know her: Metcalf won three consecutive Emmys as Jackie on Roseanne. She has recurred on Desperate Housewives and The Big Bang Theory (as Sheldon's mom), and also stars on Getting On.
The New Role: The titular clan's matriarch, Metcalf's Marjorie — which, lest we forget, may have also been Jackie's real name — has no filter, worships at the altar of Alicia Florrick and can't stand the thought of her son (Tyler Ritter) possibly moving away.
15 of 22 Monty Brinton/CBS
Katharine McPhee, Scorpion
How you know her: She sat on the floor and came in second to Taylor Hicks on Season 5 of American Idol. After a brief music career, McPhee was "Over It" and segued into acting, appearing in The House Bunny and Shark Night 3D, before spending all her time in tech on Smash.
The New Role: McPhee plays Paige, a waitress and mother of a boy genius who teams up with Walter O'Brien's (Elyes Gabel) band of socially awkward genius hackers to help them.
16 of 22 Joe Viles/FOX
Martin Short, Mulaney
How you know him: The SCTV and Saturday Night Live alum headlined three eponymous shows, including a talk show, and interviewed people as Jiminy Glick on Primetime Glick. He earned an Emmy nomination for Damages and most recently recurred on How I Met Your Mother. On the big screen, Short starred in Three Amigos and the Father of the Bride films.
The New Role: Short won't have to stretch too much for this one. He plays Lou Cannon, a legendary comedian and current game show host who hires John Mulaney as a writer.
17 of 22 Eric McCandless/ABC
John Cho, Selfie
How you know him: After ushering "MiILF" into the lexicon in American Pie, Cho went to White Castle with Kumar and plays Hikaru Sulu in the Star Trek films. He's also starred on FlashForward and Go On, and recurred on Sleepy Hollow.
The New Role: Meet your new Henry Higgins! Cho plays Henry Higenbottam, a marketing guru who attempts to rebrand Eliza's (Doctor Who vet Karen Gillan) self-absorbed, vapid image and perspective. No word if they'll recite "The Rain in Spain."
18 of 22 Michael Becker, Fox
Wilson Cruz, Red Band Society
How you know him: Cruz made history as TV's first openly gay teen Rickie Vasquez on My So-Called Life, where he hung out with Claire Danes and A.J. Langer in the girls' bathroom and rocked some killer fashion.
The New Role: Cruz plays Kenji Gomez-Rejon, a trusted R.N. in the pediatric ward. Fun fact: Red Band was created by Margaret Nagle, who guest-starred on three episodes of My So-Called Life as biology teacher Mrs. Chavatal.
19 of 22 Monty Brinton/CBS
Josh Duhamel, Battle Creek
How you know him: Mr. Fergie won a Daytime Emmy as Leo du Pres on All My Children in 2002 and then starred on Las Vegas for five seasons.
The New Role: Duhamel leaves Sin City behind for the quirky streets of Battle Creek, Mich. He plays Milton Chamberlain, a well-meaning hot shot FBI agent who's setting up a satellite office in Battle Creek, where he's forced to partner with small-town cop Russ Agnew (Dean Winters).
20 of 22 Bob D'Amico/ABC
Felicity Huffman, American Crime
How you know her: The Sports Night alum lived on Wisteria Lane for eight years on Desperate Housewives, for which she won an Emmy. Shealso received a Golden Globe and an Oscar nomination for Transamerica.
The New Role: Huffman is yet again another harried mom — this time for an entirely different reason. She stars as Barb, who's determined to find out who murdered her son Matt, a war veteran whose racially charged killing and trial is at the center of the drama.
21 of 22 Sergei Bachlakov/FOX
Rainn Wilson, Backstrom
How you know him: After a memorable recurring role on Six Feet Under as intern Arthur, Wilson rose to fame as Dwight, assistant (to the) regional manager on The Office, and Jim's favorite pranking victim.
The New Role: Think House as a cop. Wilson plays Everett Backstrom, an irascible detective with self-destructive tendencies. Instead of hobbling on a flame-emblazoned cane, Backstrom is… overweight.
22 of 22 Monty Brinton/CBS
Matthew Perry, The Odd Couple
How you know him: Could you be more clueless? Perry was there for us as Chandler on Friends and has since headlined three short-lived shows, Studio 60 on the Sunset Strip, Mr. Sunshine and Go On. He also recurred on The Good Wife.
The New Role: Perry will be messy slob Oscar to Thomas Lennon's neat freak Felix on the remake. It should be old hat after living with Monica, right?