Laura Ceron, Chuny Márquez (15 Years)(01 of15)
Open Image ModalLaura Ceron is one of six actors to appear in all 15 seasons of "ER." Ceron played Chuny Márquez starting in the Season 1 episode "Motherhood" and made her final appearance in the series finale "And In the End ..." (credit:Getty Images)
Larry Hagman, J.R. Ewing (16 years)(02 of15)
Open Image ModalLarry Hagman started playing the infamous J.R. Ewing in 1978 when "Dallas" stormed TV airwaves. The show lasted until 1991 and had two TV movies, one in 1996 and the other in 1998, before being revived by TNT in 2012. Off and on, Hagman has been portraying J.R. for 16 years. (credit:TNT)
Vicki Lawrence, Thelma Mae Crowley-Harper (16 Years)(03 of15)
Open Image ModalVicki Lawrence originated the character of Mama on "The Carol Burnett Show" in 1974 in "The Family" sketch. The sketch got its own spinoff, "Mama's Family," in 1983. It lasted until 1990 and Lawrence reprising the character from time to time in her comedy acts. (credit:Getty Images)
S. Epatha Merkerson, Lt. Anita Van Buren (17 Years) (04 of15)
Open Image ModalWhen Dann Florek departed "Law & Order" in 1993, he was replaced by S. Epatha Merkerson who played Lt. Anita Van Buren. Merkerson stayed with the show until the end, playing the same character for 17 years. (credit:Getty Images)
Richard Belzer, John Munch (19 Years)(05 of15)
Open Image ModalRichard Belzer originated the role of John Munch on "Homicide: Life on the Street" in 1993. He's appeared on more than nine different shows as Detective Munch, including "Law & Order: SVU," where he's been a series regular for 14 seasons. Belzer has played Munch for 19 years. (credit:NBC)
Peter Falk, Columbo (19 Years)(06 of15)
Open Image ModalPeter Falk became synonymous with the role of Columbo, one he played from 1968 all the way up until 2003. Falk took over the role of Columbo in the TV movie "Prescription: Murder." While he started playing the character in 1968, his appearances were not consecutive -- there were gaps in between episodes and seasons. (credit:AP)
Dann Florek, Captain Cragen (19 Years)(07 of15)
Open Image ModalDann Florek first started playing Captain Cragen in 1990 on NBC's "Law & Order." After three seasons, Dick Wolf shook up the show and replaced Florek. He returned for an episode 1995 and again in a TV movie 1998. He joined "Law & Order: SVU" in 1999 and has been with the series since. (credit:NBC)
Kelsey Grammer, Frasier Crane (20 Years)(08 of15)
Open Image ModalKelsey Grammer originated the character of Frasier Crane on "Cheers" in 1984 and portrayed the character for 20 years on his spinoff, "Frasier," which ended in 2004. Grammer also played Frasier once again in 2008 for a Dr. Pepper commercial. (credit:AP)
James Arness, Matt Dillon (20 Years)(09 of15)
Open Image ModalJames Arness starred in "Gunsmoke" from September 10, 1955, to March 31, 1975, the show's entire 20-year run. Arness also reprised the role of Matt Dillion in five TV movies from 1987 and 1994. (credit:AP)
Voice Cast of "The Simpsons" (25 Years)(10 of15)
Open Image Modal"The Simpsons" as a series started in 1989 on Fox, but the show originated as a short on "The Tracey Ullman" show in 1987. "The Simpsons" recently started its 24th season and has been renewed through Season 25. (credit:Fox)
Susan Flannery, Stephanie Forrester (25 Years)(11 of15)
Open Image ModalSusan Flannery has been around soaps for years, but her longest run has been on "The Bold and the Beautiful" as matriarch Stephanie Forrester. She was one of the few remaining original actors to appear on the soap before news broke that she was leaving in 2012. (credit:CBS)
Suzanne Rogers, Maggie Horton (39 Years)(12 of15)
Open Image ModalSuzanne Martin has been playing Maggie Horton on "Days Of Our Lives" since the show began in 1973. In 1979, Rogers won a Daytime Emmy for her work on the soap. (credit:NBC)
Susan Lucci, Erica Kane (41 Years)(13 of15)
Open Image ModalSusan Lucci fended off stalkers, kidnappers, marriage proposals and every classic soap opera trope on "All My Children" as Erica Kane from 1970 right until the show ended in 2011. Lucci's 41-year run on the soap also netted her 18 Daytime Emmy nominations and one win. (credit:ABC)
Erika Slezak, Viki Lord (41 Years)(14 of15)
Open Image ModalLike her "All My Children" counterpart, Erika Slezak spent 41 years on her ABC soap, "One Life to Live." While she didn't originate the role of Victoria Lord, Slezak took it over in 1971 and stuck around all the way through the very end in January 2012. She won six Daytime Emmys for her work. (credit:ABC)
Caroll Spinney, Oscar the Grouch/Big Bird (43 Years)(15 of15)
Open Image ModalCaroll Spinney has been with "Sesame Street" from the start. He's played both Oscar the Grouch and Big Bird since 1969, a total of 43 years. He's won multiple Daytime Emmys for his work on "Sesame Street" and two Grammys for related recordings. In 2006, Spinney was awarded a lifetime achievement award from National Academy of Television Arts and Sciences. (credit:Getty Images)