Super obsessive and manupulative male lead...

The King's Woman definitely qualifies and is really good if you study the historical part of the drama that is really intriguing.  Also a romance of sorts.

Taiwanese drama: Devil beside you has a possessive male lead.

(Other than that don't know if you are into reading manhwas or not but If you get time please read 100% PERFECT GIRL . You seen to really like this stuff so I'm sure you'll get indulged in it and will keep thinking about it like me lol. The male lead is super powerful  and possessive/obsessive it made me go crazy. It's actually unhealthy but it is love.  This is the most possessive male lead I know, jealousy in dramas are not even close to this.)

I second biaschangeseveryday's reccomendation! If you like My Heart Twinkle Twinkle you'll love this manhwa, the guy is kind of a yandere!

 TPixie_12:

Have you tried Thai Lakorns? What you are describing sound like a slap/kiss lakorn. 

If you are interested in trying Lakorns I would recommend 

Pin Anong

Cubic

Majurat See Nam Pueng

Sawan Bang (trigger warning there is rape in this one)

Mia Tuean (trigger warning there is rape in this one)

omg SAWAN BIANG <3 a must watch for people who love slap/kiss lakron!

Japanese Drama > so called “adult romance”

Kakafukaka 

HIGHLY RECOMMEND ‘ ???? but ending was eh 

Trying not to repeat too many of the ones that have already been mentioned:

Love in sadness (strongly recommend if you liked My heart twinkle twinkle)

Let me introduce her (similar to love in sadness, but I like Love in sadness better in every regard)

Missing you

Goodbye my princess (quite tragic)

I have a lover (you’ll have to wait a few episodes to see him obsessed over her, but it’s worth it :p)

My sunshine 

 Aashi:

Hey! Thanks for the recommendations but I want the obsessed lover to be the one who ends up with the h as in the my heart twinkle twinkle. It was in the end still woon tak who had heroine . Do you have recommendations  like that? Thanks ^_^

My sunshine (or You are my sunshine -there are a movie and a drama made from the same story- is about two lovers that separated due to certain circumstances (she left). When she comes back he seems to hate her (for leavinghim, since even though he seemed really cold, he loved her like crazy) but in reality you realize he couldnt forget her and had been searching for her for years, and even though he wanted to hate her he gives into his overwhelming desire to be with her. He’s quite obsessed with her and in one scene , when he thinks she is about to leave again he goes crazy XD they end up together in the end. I really love the story, both the movie and the drama!

I have a lover is about a couple who lost their daughter and their marriage is falling apart. The ml has an affair and forces the female lead to get a divorce and then leaves the country. Meanwhile, the fl has an accident and loses her memory. Years later the ml comes back and finds out she lost her memories. As he interacts with her, he realizes he still loved her all along and wants her back, but she no longer remembers him. He then pursues her in a very obsessive manner, not letting her go, and not caring about anyone and anything else that might be in his way. They also end up together :)

Goodbye my princess I wouldn’t recommend because you seem to have the same taste as me, and this drama is just too tragic!! Even though they both love each other and he is crazy obsessed with having her, the things he does are unforgivable, so it is impossible for them to have a happy ending.

.Ji Chang Wook’s character in Empress Ki was also very obsessed with our female lead (and it’s probably his best work as an actor. I would recommend it if you havent watched it yet! His character is very unique for a male lead in a drama: a coward selfish prince, resigned with being just a puppet, scared of facing the real people in power. He is very mentally unstable and ends up depending on the female lead for strength, motivation and happiness. He loves her very much and is very obsessed with her to the extreme.

Im sure you have already watched Cruel Romance, Too late to say I love you, Lady and the liar and the Kings woman so I didn’t recommend them.

There are also some other dramas that have more subtle obsession (but I don’t think this is what you are looking for) like Ten miles of Peach Blossoms (best drama ever, he loves her so so much), Love and Destiny, Listening Snow Tower, Flames Daughter. (All of them have happy endings :p)

In all of these recommendations, the female lead ends up with the obsessive guy ;)

If I remember any more, I’ll post again ;)

 gravity_:

Well intended Love  I think this might be what you are looking for.

It does not look like it at first but then there is a plot twist and basically to quote you  :

"I loved how he manupulated her into marrying him and how crazy he went when she left him"

 that also happens in this drama and as far as I remember she does go back to him.

There’s actually going to be a Season 2 of that drama! It’s quite strange actually because the ending wasnt left open. But I would agree with your recommendation. Even though it’s not a particularly good drama it fits the requirements :p