Hyun Bin

Lee Min Ho

Ji Chang Wook

Jo seung woo

Jung kyung ho

Jang hyuk

Namgoong Min (The Undateables, Chief Kim, Beautiful Gong Shim)

Lee Jun Ki (Lawless Attorney, Criminal Minds, Moon Lovers)

Park Hae Jin (Man to Man, Bad Guys, Cheese in the Trap)

Joo Won (Bridal Mask, Good Doctor)

Waaa, I have too many but the mains would be:
Yoo Seung Ho (I'm Not A Robot, The Emperor: Owner of the Mask, Remember, Missing You)
Lee Dong Wook (Goblin, Life)
Kim Jae Wook (Voice, The Guest, Temperature Of Love)
Kim Jung Hyun (Time, Eulachacha Waikiki)
Seo Kang Joon (Are You Human Too?, Entourage, The Third Charm, Cheese In The Trap)
Lee Yi Kyung (Eulachacha Waikiki, Partners For Justice, Children of Nobody)
Woo Do Hwan (The Great Seducer, Mad Dog, Save Me)
Lee Jong Suk (The Hymn Of Death, While You Were Sleeping, W)
Ahn Jae Hyun (The Beauty Inside, Blood)
Lee Jun Ho (Just Between Lovers, Wok Of Love)

Byun Yo Han (Mr. Sunshine, Six Flying Dragons)

Yoo Yeon Seok (Mr. Sunshine, Romantic Doctor Teacher Kim)

Park Bo Gum (Reply 1988, Moonlight Drawn by Clouds)

Lee Jong Suk (Pinocchio, W: Two Worlds, While You Were Sleeping, I Hear Your Voice)

Yoon Gyun Sang (Pinocchio, Rebel: Thief Who Stole People)

Jang Ki Yong (Go Back Couple, My Mister)

Kim Sun Ho (Strongest Deliveryman, Two Cops, 100 Days My Prince)

Yoon Doo Joon (Radio Romance, Let's Eat 2)

hyun bin

kim myung min

kim jae wook

It is "Joo Jin-mo" because he acted very well in the role of Wang Yoo especially showed leadership qualities by acting. 

1. Park Hae Jin

2. Kim Jae Wook

3. Lee Jong Suk

4. Lee Seung Gi

5. Gong Myung