Lots of cdramas are dubbed, but luckily there are plenty that are (mostly) not dubbed as well! I think there's a world of difference between a good dub and a bad dub, but I'll always prefer cdramas that (mostly) use their OG sound. I say 'mostly' because it can be difficult to find a cdrama that's truly 100% dub-free. Even live recorded cdramas can have the occasional dubbed line/scene (sometimes dialogue needs to be changed to pass the censors) or a random dubbed background character. Then there's curious cases like My Love, Enlighten Me where the ML is dubbed but everyone else is live recorded. Or the opposite with Who Rules The World where almost everybody is dubbed aside from like 3 side characters who seem to have live recorded audio for some reason (though I think the dubbing is very good in this one).
But anyway, I've rambled enough lol. Here's an assortment of some (mostly) non-dubbed dramas that come to mind..
Romance/Youth - Shining For One Thing, Put Your Head On My Shoulder, Summer Again
Romance - Love Is Sweet, Perfect And Casual, Moonlight
Mystery - The Long Night, A Murderous Affair In Horizon Tower, Reset
Period - The Story Of Minglan, A Dream Of Splendor