NCIS is, by many measures, one of the most successful shows of all time. For 20 seasons, we have followed Supervisory Special Agent Leroy Gibbs (Mark Harmon) and his team from the Naval Criminal Investigative Service as they investigate cases involving Navy and Marine Corps service members. In their pursuit of justice, they use tact, forensics, and gunplay. [NCIS: Los Angeles" and "NCIS: New Orleans" spawned spin-offs, both of which are now off the air; "NCIS: Hawai'i" is the only remaining spin-off (available on Paramount Plus in the US and Disney Plus in the UK). . Starring Vanessa Lachey as Special Agent Jane Tennant, who leads a Pearl Harbor-based team, the film maintains many of the original's most beloved elements.

While we wait for Season 21, here are a few more NCIS-like shows to watch.

Led by Dr. Gil Grissom (William Petersen), a team of Las Vegas forensic scientists use their skills to solve complex and often gruesome cases. They use state-of-the-art technology to find evidence to apprehend criminals, and like the NCIS team, there is a close bond between team members that is as important as the case itself.

The CSI team's work often takes them outside the lab, so there is plenty of action in this show; like NCIS, this award-winning series has spawned many spin-offs. If you're interested in the world of forensics, this is a must-see.

Available on Hulu and Paramount Plus in the US and later seasons on Paramount Plus in the UK

The core team of "Criminal Minds" are criminal profilers in the Behavioral Analysis Division of the FBI. While they use their fascinating psychological profiling techniques to tackle compelling cases, they also face a variety of demons in their personal lives.

While there were cast changes as the series progressed, the basis of the show and the premise of a close-knit team remained the same. Watching the various pieces of the jigsaw puzzle being put together by the team in each case is deeply satisfying. There have been several spin-off series, but those did not do as well as the original.

It is available on Hulu and Paramount Plus in the US and Disney Plus in the UK.

Jack Ryan (John Krasinski) is suddenly thrust from his cushy desk job as a CIA analyst into the field. Together with his friend and mentor James Greer (Wendell Pierce), he travels around the world to solve cases and stop the corruption in the organization. As time goes on, he faces more moral and geopolitical challenges than ever before.

Jack Ryan's TV series is inspired by Tom Clancy's novels. It is full of action and excitement as Ryan finds himself in increasingly dangerous situations. Krasinski plays the title role brilliantly and draws you into the development of his story over the course of four seasons.

Watch on Prime Video

After making a major mistake, River Cartwright (Jack Lowden) is committed to the Slow House, a home for failed MI5 agents. There he joins a team of misfits led by Jackson Lamb (Gary Oldman).

"Slow Horses" is one of the best shows on Apple TV Plus. This is largely due to the flawless performances of Oldman and his co-stars. The UK-based series is slower and grittier than many of its American counterparts, but still packs a punch.

Watch on Apple TV Plus

Set in the LAPD's S.W.A.T. unit, the show focuses on Sergeant Daniel "Hondo" Harrelson (Shemar Moore) as he leads a team of elite cops. In addition to physical combat, the team must also contend with issues related to race and politics as they try to protect the city and its citizens. The situations often become personal for Hondo.

If you like the action sequences in "NCIS," you will really enjoy "S.W.A.T." The show also doesn't shy away from the difficult relationships between police and various communities.

Watch on Netflix

Lily Rush (Katherine Morris), the only female detective in Philadelphia's homicide department, is assigned to an old case (a cold case) that has not been solved. For her, it is a calling, as she works diligently to solve long-forgotten crimes. The people involved often don't want to remember the past, and Rush has to bear the brunt of it.

"Cold Case" has a unique style, with each episode moving back and forth between the present and the past as the story unfolds. This provides ample opportunity to examine changes in social attitudes over the years, just as certain attitudes change over the course of "NCIS."

Available on Max in the US and Prime Video in the UK.

Habitual criminal Raymond Reddington (James Spader) and rookie FBI profiler Elizabeth Keen (Megan Boone) make an unlikely team. Together they track down the most dangerous person on the planet, putting themselves and those around them in great danger.

As with the relationships in NCSI, it will be interesting to see how the dynamic between Reddington and Keane develops over the course of the 10-season run. Meanwhile, the drama keeps us on the edge of our seats. The premise of criminals becoming accomplices with the police is often enjoyable, but it is done particularly well in "The Blacklist."

Available on Netflix in the US and Prime Video in the UK