Romance - ML not perfect...

• Cheese in the Trap
• City Hunter 
• Empress Ki - Definitely remains a jerk. Warning: there's a marital rape scene. I would describe the FL as "badass" more than "nice".
  
• Misty - The ML goes from seeming pretty decent (and on paper a very good "catch") to a truly master level jerk. "Jerk" probably isn't a strong enough word. Again I wouldn't really describe the FL as "nice". She's not a malicious person and ultimately her goals are morally sound, but she can often be rude and her confidence can come across as arrogance. 
• The Smile Has Left Your Eyes - The ML becomes much more human when he's dating the FL, but he keeps his rough edges and still makes some very bad decisions.  
• Meow, the Secret Boy - Probably not what you're looking for... The ML isn't a jerk but in terms of being "not perfect" more generally he is literally a cat. So... yeah. Some drawbacks there. 

Hello! I'm up for the challenge to find at least one drama that might fit your ask hehe. But I must say, most of those don't have a happy end. I'll hide the ending.

-Coffee and Vanilla : Now I'm just throwing everything at the wall. I did not like this drama, too vapid for my taste. But if you want an unrepentant, unjustified controlling jerk, there you have it. Happy end.

-Jealousy Incarnate: this is a cute funny kind of jerk, but he never changes. Yes, he stops being mean to her after falling for her. But he stays ego driven and superficial in my opinion. Happy ending.

-My heart twinkle twinkle: actually the ML is also the villain. The whole show is a whole exercise in "what if the jerk rich ML realizes early on that he likes the FL and gets to hide his real personality in order to get her by any means possible?" He only learns his lesson when it's way way too late . Happy ending all things considered. 

-Ngao Asoke (2008) : this jerk mistreated the FL throughout the whole show, even though she was in love with him from the beginning. At the end, he learns that she actually is a good person and what does he do to get with her? He pranks her into thinking that he's leaving her, so that she has to confess first and he just has to accept her. the ending is: happy ending. 

-Que Sera, Sera: he gets with the girl early on and doesn't change. Then things happen and he does change but not  in the puppy love kind of way. I actually think you may like this one. The ending is open. 

-The King's woman. The ending is sad. 

-The master's sun: stays uppity till the very end. Happy end.

-Too late To Say I Love You: stays scheming, ambitious to the very end. Unwilling to accept the FL unconditionally even when feeling desperate to be with her (in a "she has to be pure for me" kind of way). 

-when a man loves: he's a gangster, he wants her to see him as a gentleman but at the very moment when it matters, he's still a gangster. Bittersweet/open ending.

-oh my Ghostess: this ML is a cute pretentious type till the end . Happy end.

Hey. Thanks a lot for the suggestions both of you :).

The short description has been very useful also and I like that you wrote most of these didn't have a happy end yet majority ended up having a happy end when you wrote the description ;).

I'm not into heavy love triangle and some of these are exactly that.

That said then:

'My Heart Twinkle Twinkle' - 'Ngao Asoke (2008)' - 'Too Late to Say I Love You'.

Will def. be given a try.

The rest I've either watched and enjoyed or watched some and given up already earlier..

Also there are two versions of Ngao Asoke... Do you think 2008 is better than 2016?

I've been looking the same before so here's some people recommended to me:) https://mydramalist.com/discussions/recommendation-forum/66025-arrogant-cold-rude-ml-falls-in-love-with-naive-shy-innocent-fl?pid=1986299&page=1#p1986299 

 Dejes:

Maybe:

• Flower of Evil
• Easy Fortune Happy Life
• Jam Loey Rak
• Goong
• I Love My President Though He's a Psycho

I don't know if you are in turkish dramas but one absolutly fits your criteria! : 

Siyah Beyaz Aşk :)

I have been trying so hard for a year now to get something similar to watch like "Siyah Beyaz Ask", this drama was absolutely sensational, the chemistry between the leads in this one was out of this world and the sexual tension OMG

I don't mind if there is another drama similar along the lines to this, it can be from any country.