Action

City Hunter - It’s about the government killing their own military during this mission. There was one survivor and he ends up kidnapping his best friend’s infant son and raising him as an assassin. He sends him back to Korea as an adult to get revenge, but the young assassin ends up falling in love and it gets complicated.  - u/seashell0322

City Hunter - Military operations in North Korea and Burma, Drug-lord violence in the Golden Triangle, threat of nuclear warfare, Blue House secret service, kidnappings, revenge and murders. - u/UkEuropeEarth

I remember IRIS being quite extensive and very well made. There was lots of action and suspense with several plot twists that keeps you on your toes.  - u/kufizz

IRIS: At its airing, it was arguably the biggest blockbuster on the kdrama scene. A star studded cast, foreign locales, and big action seemed to give rise to a new type of drama that was cinematically competitive to big action movies. However, with the constant advance of the kdrama scene, the 'blockbuster' effect of this drama is no longer so apparent and the drama hasn't aged very well. It's more of a drama you should know of, rather than a must-watch.  - u/myweithisway

Time Between Dog and Wolf – A classic action romance about two brothers who join the NIS (National Intelligence Service) but are pitted against each other both by the job and their love for the same woman. Lee Joon-gi is at his action hero best, fighting his way up in a Bangkok drug cartel, wearing a deep cover mullet. The plot is nonsensical but fast moving and action packed, often unintentionally funny and always over the top.  - u/GSV_Zero_Gravitas

Two weeks - Very suspenseful and moving, the daughter was too cute. – u/kufizz

I will forever recommend Two Weeks. Really good. Little romance. - u/baitaozi

Iljimae – Starring action hero Lee Joon-gi, Iljimae is a Robin Hood type folk hero fable. As an oldschool drama, it has an intricate story with a good mix of action, comedy, political intrigue, romance and heartbreak as well as lots of sword fights, horse riding and elaborate heists. Bit of a slow start but worth immersing oneself in it. - u/GSV_Zero_Gravitas

Cruel City because oh my heck it was just the best. Drug deals, gangs, death by golf club, undercover cops, and revenge to top it all off? What is there to not love about this show? Its plot isn't driven by romance, but there is still romance and a lot of chemistry with the actors. And it is aesthetically pleasing despite the darker settings.  - u/silverbluefox

Ghost - what an incredible drama!  With So Ji Sub, Daniel Choi and Uhm Ki Joon, just a stellar cast, stellar plot, stellar everything. - u/elynwen

Healer - This is a heartwarming drama about the mysterious past of three strangers and how it connects them. It is a wonderful combination of mystery, romance, comedy, crime, detective, and a little bit of action. The pacing is tremendous, switching between all of these genres seamlessly while keeping you hooked to the story. The characters themselves are fantastically well written and acted. You are never disappointed switching scenes because every single one of the characters is interesting. It is my favorite show of all time and I think it is worth a shot if you are the least bit interested in a heartwarming mystery. – u/kdramaaccount

Girl K is an awesome mini series, I think it only has 3 episodes but it's a great story with a lot of action. - u/juhli_a

The Three Musketeers - The cast made everything special, and there were great moments throughout. And I liked how the writers kept canon but made it into a believable sageuk. Not just original story that happens to be in another country. – u/life-finds-a-way

Three Musketeers is super fun. It's based on the novels by Dumas, but interpreted in a Joseon Korean setting. Great characters, lots of different action scenes, and a good dose of comedy.  - u/lynnb496

Six Flying Dragons - Will always recommend this. Talented cast, specially Yoo Ah-In. Plot is f*cking good. Packed with action and political stuff. Gray in terms of moral, not the typical "the moral of the story is this blah blah lol". I also love the character development of every lead. 50 episodes may be long, but every episode is worth watching (walang tapon). Plus, since this has political depth and history, it's always worth discussing too. – u/derpicore 

Six Flying Dragons - Sageuk, actions, swords fighting, strategy decisions kind of drama. Some fight scenes were so intense that they are forever imprinted in my mind. - u/dfxaa

The K2 - Definitely some good fight scenes, but some part of the drama are lengthy and dramatic kind of. - u/dfxaa

K2. That tastefully blurred, naked shower room group fight.  - unknown

Lawless Attorney -  fun story, action, law and romance (same male lead as the one from two weeks). Tbh you can find a lot from him action wise. His (Lee Joon Gi) whole shtick is different versions of badass fighting male lead, from vampires to historicals, man has got it all. - u/EMarsWish

Terius Behind Me - Deals with a rogue spy who is suspected of treason hiding out in an apartment complex trying to find the real traitor who end up getting involved with a mother of 2 and ends up being their babysitter while he investigates. - u/krm787

Bad Guys (2014) – A maverick detective assembles a special task force of convicted criminals – a thug, a psychopath serial killer, an assassin – to catch even worse guys who had evaded the police in exchange of a reduction of their sentence. There is a loose “bad guy of the week” structure as well as a greater conspiracy, and each character gets their own arc too. While it’s always unabashedly fun watching Ma Dong-seok punch people, the show overall has very dark overtones. Highly recommended for anyone who does not want any romance in their action. - u/GSV_Zero_Gravitas

Seonam Girl's High School Detectives/Investigators  - A show with hard hitting topics about adolescent girls in Korea plus great action and mystery! - u/artgirlz

Chuno is probably the best action sageuk I've seen. I really like the cinematography in this bc it's not like the typical historical dramas nowadays where everything is visually aesthetic and all fluffy. This one is more gritty, but it fits the drama bc its about slave hunters. - u/jaceydarling

Three days Park Yoochun never disappoints. This was really good kept me guessing and trying to figure out what would happen next not to mention glued to my seat. About politics, secret service agents, the president and a police officer. Really good.  - u/NotMilkandHoney

W: A woman finds herself mysteriously transported into the world of her dad's comic book. And from there the mystery unfolds as to why she was able to be summoned. A great drama if you want a little bit of action and mystery wrapped together.  - u/lucidzero

Strong Girl Bong Soon: A comedy about a family of women with super strength. Solidly funny and not heavy on the action. But the action it does have is fun and enjoyable. Something more akin to an action-comedy and superhero mash up. If you want action without copious amounts of drama (not that it lacks it), this is the show for you. A great feel good action drama.  - u/lucidzero

Fiery Priest A catholic priest who can fight with his hands. Nuns who state their mind and a female lawyer who might or might not join the fight against corruption.  - u/the-other-otter

Is Vagabond worth all the hype? In a technical aspect (fight scenes, production value, cinematography, and sets? YES!! In term of plot, story, and acting, no, it’s not worth the hype. It’s an overall fun show where you can shut off your brain and watch and still enjoy it. Logical thoughts should be excluded! - u/ProdigiousTrue

Dude, Vagabond is the fucking best. Personally I like more fantasy romance things but the action and romance as well as the executions of Vagabond as a show is like duh best. Honestly it’s great because it’s also fairly realistic in terms with relationships and reasoning, unlike most kdrama with those stupid cliches that make me cringe personally. But like I’m not good at explaining things and I promise it’s 10x better then I make it sound.  - u/mongril

Vagabond - It's very good. Well shot, well acted, good plot. You'll get the answers but you won't get resolutions. Last episode is bonkers though.  - u/RayInRed

My Country - There's plenty of action when you have the two best swordsmen of the early Joseon period pitted against each other during the rebellion that brings King Sejong to power.  One of them is also an excellent archer and strategist.  - u/LcLou02

Descendants of the Sun - This is more of a rom-com melodrama, but since the setting is of the South Korean soldiers there’s lots of action! Quite a lot of things keep happening in the drama without a break and so there’s always something to look forward to. The main couple and the second couple have great chemistry and the drama has some witty and funny dialogues. I also loved the cinematography and soundtrack of the drama. It’s an enjoyable action melo rom-com with some slice of life thrown in here and there. - u/Fatooz

Kingdom (Season 1 and 2) - Kingdom is one of the most exceptional dramas I've seen, with thrilling and suspenseful scenes scattered throughout, complemented with exceptional action set pieces. The mix of historical politics with a zombie action thriller plotline really makes for a unique show to watch. Add to that the exceptional direction and cinematography, Kingdom is one of the best dramas out there, in my opinion.  - u/TotoroTheGreat

multiple seasons

The Uncanny Counter - It’s an action fantasy crime thriller which was surprisingly super wholesome. I loved the team work of the main four characters and there was some fabulous action! It keeps you on the edge of your seat at least for the first half. The second half was a bit less exciting compared to the first half but it still finishes strong and it’s a fantastic drama.  - u/Fatooz

The Uncanny Counter is worth watching because it is a refreshing and unique fantasy action drama where the main characters fight against evil spirits. There is a strong bond for the "Counters" team. Viewers may enjoy the action seasons and how there are many evil characters that need to be fought. Hoping for a Season 2 soon! - u/dramafan1

Vincenzo - This is another crime action thriller, loved the action in this one. It has great acting, plot, soundtrack and cinematography. It gives such theatrical feel and although it takes time to get into it, once you’re past the 4th episode it’s just amazing!  - u/Fatooz

Vincenzo - also, law mixed with action and even more action. This is one of my fav drama of this 2021. Great actors, comedy, little romance and super action.  - u/DonLini

Live is more of a slice of life drama, depicting the travails of police officers in  a  patrol division. But there's still some action every episode, as the officers cope with a variety of crimes. This is an ensemble drama with a large cast. It will tug at your heart strings, alternately making you hang your head in despair or cry with happiness. Live is well worth a watch! - u/Longjumping-River-42

Taxi Driver is an excellent action revenge drama from the beginning to the end. It is based on real life crimes in South Korea and the concept of a taxi revenge service is thrilling. The fight scenes and car chase scenes are very satisfying to watch. Once again, Lee Je Hoon has acted in another great drama! This drama is a must watch for viewers who prefer action, revenge, and no romance. - u/dramafan1