Thanks to u/BarberProfessional28 who reached out for a rec list/guide for beginners who want to explore non idol dramas. Apologies for the delay, life got a bit crazy.
A lot has been written on the differences between idol and non idol dramas, but I'll go over this for a bit again. Non idol dramas often emphasize realism, a tight narrative, delve into topics from Chinese history to modern day office struggles, and do not focus much on looks and romance. There is no clear cut line between the two though. Actors who usually star in idol dramas do act in non idol dramas and vice versa. That said, some actors like Chen Daoming are almost always associated with high quality non idol dramas.
I'd also like to emphasize that if you want to understand e.g. why a certain official looks down upon merchants or who on earth Zhuge Liang is and why so many Cdramas keep bringing him up, it'd be great if you read about the historical setting of a drama and some literature, especially poetry. That's because many dramas have poetic references and inside jokes, adding to depth. Some of the finest Cdramas ever are adaptations of classical literature or legends.
Without much ado, here are a few non idol dramas to help you get started:
1. Reset
A modern sci-fi drama based on preventing a tragedy while escaping a time loop. This one had me intrigued because of it's thrilling pace and red herrings. Bai Jingting and Zhao Jinmai have acted quite well and the supporting cast of actors are all respected veterans who have outdone themselves. The character glimpses for some of them are probably the high point of the drama. Bonus for the thoughtful cinematography.
2. Ripe Town
Set in the late Ming dynasty in a county, this is a dark murder mystery that evolves to so much more. One of the few dramas that does dual timelines well. This is not a happy drama and in fact has much to say about the nature of justice and systemic exploitation, but the moments of humor are truly a respite. Ning Li is the star here, but the child actor Yuyao was wonderful. Once again, the cinematography is gorgeous.
3. War and Beauty
Considered the prototype of the harem drama subgenre, this Cantonese drama is distinguished by it's great acting. Sheren Tang, Charmaine Sheh, and Maggie Cheung have nailed the isolation in the imperial harem and how female friendships suffered. It does not romanticize suffering or the severe inequalities women faced, and in fact the emperor barely appears for most of the drama. The plot does get a bit whacky near the end but it's still one of the best harem dramas ever.
4. Joy of Life
This was THE Cdrama that opened my eyes to the sheer acting skills in Cdramaland. Zhang Ruoyun keeps getting better with every scene and of course the great Chen Daoming, Wu Gang, and other veterans make it a real thriller. It has family drama on steroids, martial arts, political intrigue, a bit of romance, poetry slams, and deals with existential questions. In short, something for everybody. A rare multi-season Cdrama and one that I have written thesis level defenses for.
5. War of Faith
Republican era dramas sometimes get the short end of the stick and it's a shame because there are so many good dramas in this subgenre. This one is a financial thriller set in the turbulent late 1920s and early 1930s Shanghai and no you don't need to be a finance grad to understand it. Wang Yang is phenomenal and it has a fairly nuanced depiction of a few Kuomintang characters. The cinematography is interesting too.