T/n: complete title of the post is “Actors who created a buzz for appearing in MVs that could be put into their filmography”
1. Clara (Park Jaebum – Joah)

2. Jang Dongyoon (BOL4 – Galaxy)
3. Ha Jungwoo (Big Mama – Betrayal)
4. Choi Woosik (Day6 – You Were Beautiful, Congratulations)
5. Lee Sungjae (Gain – Irreversible)
6. Joo Jihoon (Gain – Fxxk U)
7. Nam Joohyuk (AKMU – 200%)
First of all, this is what OP can think of…
There might be more
I might not be aware of them
Anyways… there are more
original post: here
1. Kim Heejung is Sik-K’s Rendezvous was the real deal
2. I screamed 200% Nam Joohyuk while clicking in this
3. Wow I agree with Nam Jooyhuk and Choi Woosik
4. Lee Junki…
5. Nam Joohyuk seriously needs to put that in his filmographyㅋㅋㅋㅋ
6. I saved that Joo Jihoon candle gif 5 times
7. Why is Jang Kiyong in Friday not here ㅠ
8. Clara seriously looked so pretty in that MV and came out looking so charming
9. I clicked in thinking about Nam Joohyuk ㅋㅋㅋㅋㅋㅋ
10. I knew that Nam Joohyuk would be here ㅋㅋㅋㅋㅋ
11. I seriously watched that MV so many times for Lee Sungjae,,,
12. Seo Inguk isn’t here…
13. I thought that Seo Inguk would be here ㅋㅋㅋㅋ
14. I screamed Choi Woosik… Jang Heeryung needs to be included too… (T/n: the actress in Day6’s MVs)
15. I like Jang Dongyoon. He’s the epitome of refreshing
16. Suzy in First Love ㅠㅠ
17. Nam Joohyuk is f*cking heart fluttering