Just for fun. Cite a recurring thing in KDramaland that you're almost guaranteed to see in a drama.

I'll start with: Dangerous driving. It's a broad phenomena and it's not even restricted to specific genres — it occurs in just about every drama that has a vehicle in it. Whether it takes the form of illegal U-turns, checking phones, running at full speed on the lane (while cutting everyone through traffic) or driving in extreme emotional states (most likely to end up in a serious accident, lesson learned at least), you can bet you'll find at least one of them in your next drama.

And remember, kids, don't drive while you're crying your eyes out. Your turn.

lead actress/2nd lead actress being drunk
XD

There being a misunderstanding because the lead actor/ess talked to a member of the opposite sex who is not their romantic interest.
An ex ALWAYS shows up when things are going well for the main guy and the main girl and then chaos and frustrations starts! 
The male lead is sick/have a fever then the female lead is taking care of him. hahaha i feel like this is happens in every kdrama XD
Someone's family is always against the relationship... Come on!!!
the dude buys the girl a drink from one of those vendingmachines
an obvious one,main guy treats girl like trash,but still gets the girl
There is at least one imprisonment/torture/interrogation episode in every single historical kdrama (i'm not exaggerating)
karoke, especoally in historical dramas :)
Male and female lead walking in the street or some other way when some vehicle popps up and the male lead 'saves' the girl and slowmotion ,romantic music, girl falls for male lead (for a moment) 
If it is raining and there is no umbrella, the character will always get a raging fever worthy of near death and nothing can cure it except for the other lead to nurse them back to health.