Which actors/actresses do you think have the most on screen and/or off screen chemistry? For example, I'm seeing Hyeri & Jang Ki-yong promote together and OML!! Off the charts even though Ik she's booed up. On the other hand, I'm struggling to see it with Seo In Guk and Park Bo Young in "Doom, at your service." That man is my number one actor and I think he has raving chemistry with anyone he acts with as does she, but I'm not feeling a SPARK. Off screen them isn't doing it for me either??? I thought the same of Song Joong Ki & Jeon Yeo-been for a short time, but by the end of the drama those two are really a duo off and on screen. 

Any opinions??! 

Chae Soo Bin with anyone, but best was Yoo Seung Ho in I am not a robot

Jun Ji Hyun with Kim Soo Hyun in You who came from the stars

Wan Peng with Riley Wang in First Romance (not korean)

All are good also in BTS.

I don't know about off-screen chemistry since I can't follow that, and I'll name the series too lazy to name the actors atm, but they are the ML/FL:

Crash Landing on You     (actually dated RL)
Hana Yori Dango   (jdrama of boys over flowers)
I'm Not a Robot   
Strong Woman Do Bong Soon    (actually ML wanted to date FL in RL)
Secret Garden   
Weightlifting Fairy Kim Bok Joo    (actually dated RL)
The King: Eternal Monarch    (no matter what anyone says, I thought they had good chemistry)

I'm still new to k-dramas and have a lot of catching up to do, but from what I've seen, it's So Ji Sub and Gong Hyo Jin in Master's Sun for me. Chemistry was off the charts with those two.

- Cho Seung Woo & Bae Doo Na (Strange 1/2)- There wasn't even any romance in Stranger 1&2, but their chemistry was so good

- Yeo Jin Goo & Lee Se Young (Crowned Clown) - Their offscreen chemistry is so natural/light and that's why their on screen chemistry was definitely good

- Jung Il Woo & Kwon Yuri (Bossam steal the fate) - Many commented their chemistry was so cute because they always hang out offscreen

- Kim Nam Gil & Lee Ha Nee (Fiery Priest) - I have no words for this charismatic chaotic duo. The drama itself is a proof of their chemistry

- Ji Sung & Kim Min Jung (Devil Judge) - It was the first time seeing them both in a drama I am watching and I was amazed by their interactions. Both onscreen and offscreen they are too charismatic. It was said they star in a drama together before so no wonder why they are natural with each other. 

- Park Seo Joon and Kim Ji Won - Their chemistry on and off screen was just so natural in Fight For My Way  cannot even compare

Kim Nam Gil & Lee Ha Nee  

Ji Chang Wook and Ha Ji Won

Descendants of the Sun 

the best chemistry is between Song Joong-ki and Jin Goo ❤️?❤️

Song Joong-ki+ Song Hye Kyo❤️

Jin Goo + Kim Ji Won❤️

Her private life 

Kim Jae wook+ Park Min Young ❤️

Touch your heart 

Yoo Inna + Lee Dong Wook ❤️

The Masters Sun  

So Ji Sub + Gong Hyo-jin❤️

Semantic Error  -  Park Seo Ham  &   Park Jae Chan 

A Business Proposal  -  Ahn Hyo Seop  &  Kim Se Jeong   +  Kim Min Gue  &  Seol In Ah 

Rookie Historian Goo Hae Ryung  -   Shin Se Kyung  &  Cha Eun Woo 

To the Beautiful You  -  Sulli  &  Choi Min Ho 

True Beauty  -  Moon Ga Young  &   Hwang In Youp

Weightlifting Fairy Kim Bok Joo  -  Lee Sung Kyung  &  Nam Joo Hyuk 

What's Wrong with Secretary Kim  -  Park Min Young  &  Park Seo Joon

Give me these on a screen and I think I could watch even the  worst k-drama lol ...

Gong Yoo + Kim Go Eun (Goblin)

As someone who never watches Kdramas for the romance, I will forever ship the main couple from Hyena because of how Kim Hye-soo and Ju Ji-hoon's insane chemistry swept me off my feet. 

Kim Soo Hyun and Seo Yea Ji <3 -it's okay not to be okay