Choi Jin Hyuk (Devilish Joy) except without the amnesia part - I fell for his character within the first half of episode 1!
Seo Ha Joon (Phoenix 2020) 2nd ML who is sweet/flirty and makes the FL giggle with his jokes. Despite the negative comments/low ratings I enjoyed watching his character and romance with the FL more than the original 2004 version, I found him way more attractive both looks/personality compared to Eric Mun's Jung Min.
Seo Kang Joon (Are You Human Too?) he might be a robot but I would love him if he existed IRL. He pulled off the "perfect boyfriend" role better than Yeo Jin Goo's My Absolute Boyfriend character imo he had more of the looks/stage presence to be an actual adaption of the character Night Tenjo.
Kim Jae Wook (Her Private Life) also sweet/perfect BF <3