Hmm, this is something to consider.
1. Oh Jihyeok (Good Detective, 2020)
Because he was kind, loyal and smart.
2. On Jeongseon (Temperature of Love, 2017)
Smart, kind, understanding, honest, upfront.
Honorable mentions:
Kim Dohyeong (My Beautiful Bride, 2015). The fact it's Kim Muyeol has nothing to do with it. I am absolutely unbiased.
A man who, quite literally, can tear people apart for his love.
Lim Eunseob (When The Weather is Fine, 2020)
Because he always had warm tea/coffee waiting.
Ji Guk (You're All Surrounded, 2014)
Because I said so.