Some of the most common things which I have seen/read like all the episodes stories are:
1)Detective/ Assassin
MC no matter how tough she’s shown will fall for her target or her partner.
2)Club Scene
Story shows MC is shy or like a misfit or an introvert but there has to be an obligatory Club Scene, even if it makes no sense.
3)Rich Vampires/ Warewolves
Any story relating them will show that they own Pvt jets, Large Mansion etc but will never show them working lol.
4)Falling for new Secretary
Owner just came out of a relationship n immediately fall for the new assistant he hired
5)Jealous Ex girlfriend
Every story will have this jealous ex gf n her minions who will try to go to any extent to hurt the MC
6)MC n his Best Friend being Playboy
Every college drama this is used
7)Uninvited Guest
Another of those college romance thing where a party is thrown n MC best friend says they have to go even if they are uninvited
8)Supernatural Prodigy
Another of those stuffs where the MC is some sort of Prodigy born to either become a goddess or to kill the evil character she has some beef wit
9)Falling for the murderer or Smuggler
MC learns that her lover killed her parents n now thinks she should accept his/her apology or MC was kidnapped n then she magically changes him
10)Naive MC
Most of the stories have this pious innocent sort of MC who has this crush on the bad boy of the story.
These are some which are like over used in almost all the genres. Some stories are like exact replica of the one you just read few months back(like most of the Vampires/Warewolves stories) n some losses the plot mid way and becomes uninteresting by the time it ends.