Duang Duang Haruetai is similar to Chaloey Sak because of Kingdom plots and prince/princess becoming prisoner for political reason and both ML and FL fell in love.

Ka Badin is similar to Nueng Dao Fah Diew because both are historical lakorns where the main male lead is fighting for Thailand.

Pitsawat is similar to Sri Ayodhaya because both lakorns are time travelling lakorns set during the fall of Ayodhaya in 1767.

Amaraetalai is similar to Sin Lai Hong because both lakorns are starring during the SUKOTHAI period.

Look Tard is similar to Nang Tard because of the slavery theme and then the slave gains its freedom at the end of the drama.

Chaat Payak is similar to Look Tard because of the main male lead slaevery theme.
The slave male lead gains his freedom after slavery abolition in Thailand under RAMA V and is in love and marry the rich female lead.

Ubathteehet is similar to Kluen Cheewit because of the plot.
1) The male lead is from a modest family and earn his life from a honorable job
2) The female lead is a rich woman who seems to be extravagant and unreasonable
3) A car accident happens and the female lead killed the male lead girlfriend
4) The male lead takes revenge on the female lead by raping her

Bad Romeo is similar to Winter Sonata because both are melodramas which start when the ML and the FL were young adults and fall in love then a tragedy set them apart for 7 or 10 years.
Then when the female lead sees the ML years after with a new identity and happens to work for him, she cannot ignore him and forget the past even if the ML pretends not to know her at all. Therefore a new story starts between them and the love flame is up again...

Poisonous Passion is similar to Sai See Plerng because of the vengeful charming main actress theme, who tries to seduce several men at the same time.

Nam Sor Sai is similar to Plerng Boon because of the love triangle theme between the husband, the main loyal wife and the lover woman.

Mia Luang is similar to Plerng Boon because of love triangle them between the husband, the main loyal wife and the lover woman.

Ruk Lork Lork Yah Bork Krai is similar to Ruk Nid Nid Kid Tow Rai because of the fake boyfriend/girldfriend them to avoid the main actor/actress to be forced to marriage by their parents. Both are comedies.