10 Longest-running TV Shows

Bart Simpson, Lisa Simpson, Homer Simpson, Marge Simpson and Maggie Simpson visit The Empire State Building to celebrate the 30th anniversary of "The Simpsons" at The Empire State Building on Dec. 17, 2018 in New York City. Noam Galai/Getty Images

Who would have thought that an animated sitcom featuring a family of severely jaundiced-looking, accident-prone oddballs would have made it this far! The AVClub has called it "the best animated series of all time, and television’s crowning achievement regardless of format." With more than 700 episodes in the can, its longevity is leagues ahead of any other show.

Ice-T (behind), Demore Barnes (left) and Mariska Hargitay are seen on the set of "Law & Order: Special Victims Unit" on Feb. 24, 2021 in New York City. Jose Perez/Bauer-Griffin/GC Images

If you like a good crime drama, "Law and Order: SVU" is probably on your guilty pleasures list. It’s also the only live-action primetime television show that debuted in the 20th century and is still running. Over the course of over 500 episodes, main character Olivia Benson, played by Mariska Hargitay, has investigated sex crimes of all kinds, and has been promoted up the NYPD's 16th precinct’s ranks, from detective to captain. "Law and Order: SVU" has made Olivia Benson the longest-running main character in any live-action primetime show.

In a still from the CBS series "Gunsmoke," with Ken Curtis (left) watches as James Arness aims a gun in the episode titled "The Raid - Part I." Bettmann/Getty Images

"Gunsmoke" tops the list as the longest-running dramatic series in network television history with 635 episodes. Set in Dodge City, Kansas, during the 1870s, "Gunsmoke" began as a radio program in 1952, switched to the land of visual entertainment in 1955, and finally ended its 20-year run in 1975.

Unlike its spinoff "Law and Order: SVU", "Law and Order" had an undeniably good run, but not without interruptions. This successful police procedural sired six spinoffs and a made-for-TV movie, and lasted an incredible 20 seasons and 456 episodes. In 2010, after 20 years on air, NBC cancelled "Law and Order," and after an unsuccessful attempt to shop it around to three networks, "Law and Order" became a thing of the past. Until 2021, when NBC announced "Law and Order" would come back with a new season in 2022.

"Family Guy" follows the hilariously offbeat Griffin family. FOX/Getty Images

It seems Americans love animated sitcoms about dysfunctional families. "Family Guy" premiered in 1999, and 20 seasons and almost 400 episodes later, we're still turning in to find out what kind of trouble a diabolical baby and an anthropomorphic dog will get into.

Lassie (actually son of Lassie) and costar Tommy Rettig watching themselves on their TV show "Lassie." John Bryson/Getty Images

Running for 588 episodes, "Lassie" centered around a loyal canine companion who rescued her human family from various predicaments. Over the years, Lassie was portrayed by nine different male dogs, all descendants of the original Lassie, whose real name was Pal. During the show's run, Lassie had various owners, most notably Timmy and Jeff. Only three dogs have a star on the Hollywood Walk of Fame — Lassie, Rin Tin Tin and Strongheart.

A blend of police procedural and military drama, "NCIS" follows a team of criminal investigators for the Navy, solving everything from poisonings to terror attacks. Premiering in 2003, "NCIS" is approaching 450 episodes.

"Grey's Anatomy" focuses on the lives of surgical interns, residents, and attendings as they balance personal and professional relationships in a hospital setting. ABC

If you have ever received medical advice from someone who was not a health care professional, it's possible they've been watching "Grey's Anatomy" for a couple of decades. Premiering in 2003, its ABC's longest-running scripted primetime show, and after all these years remains one of the most watched shows on broadcast television. After 18 seasons and almost 400 episodes, we still can't wait to find out what's going to happen once the surgical interns, residents and attending physicians scrub in.

"American Dad!" is an adult animated sitcom created by Seth MacFarlane, Mike Barker and Matt Weitzman for the Fox Broadcasting Company. TBS

Since its debut in 2005, "American Dad!" has served up 18 seasons of the animated family sitcom chuckles America loves. Republican dad with a humongous chin? Check! Existentially addled teenaged children? Check! Pet goldfish that thinks it’s a German elite athlete? Check? Neurotic alien pet? Well, you get the idea.

"Somebody in Las Vegas has been murdered! But who did it and how?!" That’s the basic premise of "CSI: Crime Scene Investigation." Consult a gas spectrometer and recruit an exotic dancer into the police force as blood splatter specialist and you’ve got yourself a forensic crime drama! CSI ran for 15 seasons and produced 337 episodes of grizzly who-done-its.

Originally Published: Sep 15, 2007