1. NCIS: Los Angeles
The exploits of the Los Angeles–based Office of Special Projects , an elite division of the Naval Criminal Investigative Service that specializes in undercover assignments.
It has an average vote of 7.557 on TMDB.
2. NCIS: New Orleans
A drama about the local field office that investigates criminal cases affecting military personnel in The Big Easy, a city known for its music, entertainment and decadence.
It has an average vote of 7.4 on TMDB.
3. Hawaii Five-0
Steve McGarrett returns home to Oahu, in order to find his father's killer. The governor offers him the chance to run his own task force . Steve's team is joined by Chin Ho Kelly, Danny "Danno" Williams, and Kono Kalakaua.
It has an average vote of 7.724 on TMDB.
4. Law & Order: Special Victims Unit
In the criminal justice system, sexually-based offenses are considered especially heinous. In New York City, the dedicated detectives who investigate these vicious felonies are members of an elite squad known as the Special Victims Unit. These are their stories.
It has an average vote of 7.966 on TMDB.
5. Criminal Minds
An elite team of FBI profilers analyze the country's most twisted criminal minds, anticipating their next moves before they strike again. The Behavioral Analysis Unit's most experienced agent is David Rossi, a founding member of the BAU who returns to help the team solve new cases.
It has an average vote of 8.322 on TMDB.
6. The Flash
After a particle accelerator causes a freak storm, CSI Investigator Barry Allen is struck by lightning and falls into a coma. Months later he awakens with the power of super speed, granting him the ability to move through Central City like an unseen guardian angel. Though initially excited by his newfound powers, Barry is shocked to discover he is not the only "meta-human" who was created in the wake of the accelerator explosion -- and not everyone is using their new powers for good. Barry partners with S.T.A.R. Labs and dedicates his life to protect the innocent. For now, only a few close friends and associates know that Barry is literally the fastest man alive, but it won't be long before the world learns what Barry Allen has become...The Flash.
It has an average vote of 7.795 on TMDB.
7. CSI: Crime Scene Investigation
A Las Vegas team of forensic investigators are trained to solve criminal cases by scouring the crime scene, collecting irrefutable evidence and finding the missing pieces that solve the mystery.
It has an average vote of 7.663 on TMDB.
8. CSI: Miami
CSI: Miami follows Crime Scene Investigators working for the Miami-Dade Police Department as they use physical evidence, similar to their Las Vegas counterparts, to solve grisly murders. The series mixes deduction, gritty subject matter, and character-driven drama in the same vein as the original series in the CSI franchise, except that the Miami CSIs are cops first, scientists second.
It has an average vote of 7.757 on TMDB.
9. Grey's Anatomy
Follows the personal and professional lives of a group of doctors at Seattle’s Grey Sloan Memorial Hospital.
It has an average vote of 8.3 on TMDB.
Dr. Gregory House, a drug-addicted, unconventional, misanthropic medical genius, leads a team of diagnosticians at the fictional Princeton–Plainsboro Teaching Hospital in New Jersey.
It has an average vote of 8.595 on TMDB.
11. Marvel's Agents of S.H.I.E.L.D.
Agent Phil Coulson of S.H.I.E.L.D. puts together a team of agents to investigate the new, the strange and the unknown around the globe, protecting the ordinary from the extraordinary.
It has an average vote of 7.492 on TMDB.
Dr. Temperance Brennan and her colleagues at the Jeffersonian's Medico-Legal Lab assist Special Agent Seeley Booth with murder investigations when the remains are so badly decomposed, burned or destroyed that the standard identification methods are useless.
It has an average vote of 8.268 on TMDB.
13. The Blacklist
Raymond "Red" Reddington, one of the FBI's most wanted fugitives, surrenders in person at FBI Headquarters in Washington, D.C. He claims that he and the FBI have the same interests: bringing down dangerous criminals and terrorists. In the last two decades, he's made a list of criminals and terrorists that matter the most but the FBI cannot find because it does not know they exist. Reddington calls this "The Blacklist". Reddington will co-operate, but insists that he will speak only to Elizabeth Keen, a rookie FBI profiler.
It has an average vote of 7.615 on TMDB.
14. The Mandalorian
After the fall of the Galactic Empire, lawlessness has spread throughout the galaxy. A lone gunfighter makes his way through the outer reaches, earning his keep as a bounty hunter.
It has an average vote of 8.465 on TMDB.
15. Breaking Bad
When Walter White, a New Mexico chemistry teacher, is diagnosed with Stage III cancer and given a prognosis of only two years left to live. He becomes filled with a sense of fearlessness and an unrelenting desire to secure his family's financial future at any cost as he enters the dangerous world of drugs and crime.
It has an average vote of 8.889 on TMDB.
16. The Big Bang Theory
Physicists Leonard and Sheldon find their nerd-centric social circle with pals Howard and Raj expanding when aspiring actress Penny moves in next door.
It has an average vote of 7.877 on TMDB.
When they were boys, Sam and Dean Winchester lost their mother to a mysterious and demonic supernatural force. Subsequently, their father raised them to be soldiers. He taught them about the paranormal evil that lives in the dark corners and on the back roads of America ... and he taught them how to kill it. Now, the Winchester brothers crisscross the country in their '67 Chevy Impala, battling every kind of supernatural threat they encounter along the way.
It has an average vote of 8.302 on TMDB.
The adventures of Ragnar Lothbrok, the greatest hero of his age. The series tells the sagas of Ragnar's band of Viking brothers and his family, as he rises to become King of the Viking tribes. As well as being a fearless warrior, Ragnar embodies the Norse traditions of devotion to the gods. Legend has it that he was a direct descendant of Odin, the god of war and warriors.
It has an average vote of 8.085 on TMDB.
Spoiled billionaire playboy Oliver Queen is missing and presumed dead when his yacht is lost at sea. He returns five years later a changed man, determined to clean up the city as a hooded vigilante armed with a bow.
It has an average vote of 6.792 on TMDB.
20. SEAL Team
Military drama following the professional and personal lives of the most elite unit of Navy SEALs as they train, plan and execute the most dangerous, high stakes missions our country can ask of them.
It has an average vote of 8.038 on TMDB.
A modern update finds the famous sleuth and his doctor partner solving crime in 21st century London.
It has an average vote of 8.537 on TMDB.