Sud Sai Pan is really similar to Song Naree :
-same plot
-twin sisters separate at birth
-older one raised by her father and nice girl
-younger one raised by her mother and bad girl
-male lead confused between the twin sisters identity

Rottanakosin is similar to Ka Badin because both are starring during Rottanakosin thai period and age gap between ML and FL.

Sai See Plerng is similar to Poisonous Passion because the main lead actress is a brillant woman who seduces several men.

Buang is similar to Paap Ataan because of the vengeful horror theme that involves an woman gost who doesn't want to end up with revenge on male lead and female lead and does not want to reincarnate.

Tae Pang Korn is similar to Roy Mai because of reincarnation theme and obstacles the ML and FL have to overcome beyond 2 lives.

Tae Pang Korn is similar Buang Wan Wan because of the love triangle plot through 2 or 3 lives.
In each life, the love between ML and FL has to overcome obstacles put by the evil FL.

Roy Ruk Roy Adeed is similar to Tae Pang Korn because of an eternal love couple separated in the past life by a cruel woman who loves the male lead and could not support for them to get married.
In the new life, the same plot is starting again with this love triangle.

Duay Rang Athitarn is similar to Klin Kasalong because the female lead who loves the same man as her half sister/twin.
She then was jailed and starved to death before her dead body was discovered by the male lead.
She then wished to get revenge on all the people who made her suffer in the past life.

Sin Lai Hong is similar to Klin Kasalong because the FL was stab to death in the past life and swear to get revenge in the new life.

Duay Rang Athitarn is similar to Klin Kasalong because the female lead who loves the same man as her half sister / twin.
She then was jailed and starved to death before her dead body was discovered by the ML.
She then wishes to get revenge to all the people who made her suffer in the life.

Duay Rang Athitarn is similar to Sin Lai Hong because of the femal weak male lead who was tortured to death in the pas life makes wished to born stronger and get revenge on her ennemies in her new life.

Plerng Pranang is similar to Rak Nakara because both involved foreign kingdom with political issues. Set in the end of 19th century.