1-Hate turns into love
So this is like the biggest cliche ever. The boy is an asshole and the girl is that annoyed clumsy girl and somehow they end up meeting and it always goes with the boy flashing a smile, using charisma to get out of the situation and the girl yelling.
And as magical as it sounds, they end up seeing each other again and again. It's considered a coincidence but the truth is that the writer just pulled up the olderst trick in the book.
It's another big cliche to throw in a hot but not as hot as the main boy in the picture. The new boy usually comes when the main characters are going through something though and the new boy always confuses the girl and makes us hate the girl for doubting her love.
And every now and then this new boy is platonically in love but we see his love affecting the girl and pulling her in. It always ends up with jelousy and it's usually cute but the writers don't know when to stop. They turn the situation into shit or even make the new boy the main girls boyfriend. Those situations are the worst and the ratings go down as soon as that happens.
This is not as usual as the other two but it is a common pattern. It's either a psycho killer in their life or a rapist or a perv. It happens and if you are unlucky, they turn it all upside down and then you end up with the "DID HE RAPE YOU? ARE YOU NOT PURE ANYMORE?" cliche and then you just turn the fucking TV off and cry yourself to sleep because ANOTHER SHOW RUINED.
I can't think of any other cliche right now but I think these are the biggest cliches. I might come up with new ones and make a new series out of it, I dunno.