I think these actors will really suit the roles. I can imagine Jung Hae In and Go Yoon Jung and Lee Jae Wook as the leads. However, if hidden Love has a korean adaptation I will be very happy regardless of who the actors are.
For the male lead (Duan Jia Xu) I imagine quite a few actors, such as Byeon Woo Seok, Song Kang, Lee Jong Suk & Lee Junho. As for the female lead (Sang Zhi), maybe actresses like Kim Se Jong, Kim Hye Yoon, Seol In Ah & Kim Yoo Jung. I think Lee Seung hyub or Oh Se Hun can take the role of Sang Zhi's brother - Sang Yan. It's really hard to choose because there are so many actors/actresses who fit the role in my opinion. But if I had to choose only 2 of them, it would be the couple from My demon - Kim Yoo Jung and Song Kang. How about you? Who do you imagine as the main leads?
Most highly rated dramas especially kdramas ARE overrated....i cant complete most of them including goblin and…
I'm not sure you'll like them because I don't know what genre you like, but if you're into romantic comedies I'd recommend "Her Private Life" ; "Still 17" (also known as Thirty but seventeen); "Doom at your service". I know these aren't the most unknown dramas, but compared to others I rarely hear anyone who has watched them and is talking about them. So if you haven't seen them, give them a chance if you want. :)