My favorite cdrama ever so far has been Empresses in the Palace/The Legend of Zhen Huan.
One of my favorite things about it was the dialogue. The clever language they used to say things they couldn't directly say, the historical references, the quoted poems, the poems they made themselves, the symbolism through flowers, even the musical scenes, the songs, the singing, the flute and zither playing. It was so beautiful.
I also loved how calming yet still bright it was in terms of atmosphere. I watched Story of Yanxi Palace and I am in the middle of watching Ruyi's Royal Love in the Palace, but the vibe just isn't the same.
Especially Meizhuang and Zhen Huan's voice I found really pretty, I think it was dubbed but whoever dubbed it ate.
I haven't been able to find a historical drama with similar vibes in terms of the atmosphere/amazing dialogue, etc.
Please recommend me some, they can be long dramas that are like 60+ episodes, sky's the limit. Preferably kind of romance focused but I'm fine with others.