I guess I am quite late but maybe my list could help.
Now there are 3 types of obsessed leads you will see:
Type 1- Cute obsessed: MLs are cute, you will get butterflies in your stomach. This is the type which will make you believe in true love and happy endings. Typically set in a college/office environment. Keep in mind, sometimes MLs do lose their interest with time and the obsession tones down a bit. Recommendations: Flower boy ramen shop, boys over flowers, hana yori dango, meteor shower, 9 to 5 (jap), Love 020, the greatest love, boss and me, gunesin kilzari (turkish), noble my love, witch's love, murphys law of love etc. You can start with Flower Boy Ramen shop.
Type 2- Dark obsessed: MLs are jerks but they will make you feel sexy and bold. They may manhandle (pin against wall, force hugging etc.) but no rape or physical torture. These dramas will keep you on edge because you never know whats going to happen next. Typically revenge and/or misunderstanding scenarios. Recommendations: Secret, Siyah Benaz Ask (best ever), Khaani (south asian), I love my president but he is a psycho, well intended love, autumn's concerto, summer's desire, behind your smile etc. Their attitude may get better with time but their obsession stays the same. You can start with "Well intended love".
Type 3: Cruel obsessed: There is no line they won't cross to make sure you stay with them. Dark, torture, rape, physical force, blackmailing. Recommendations: Cruel romance, sawan biang, game rai game rak, le jun kai, I am not a big fan of this type but have seen a few of them just to satisfy my curiosity. Even if you watch them, you will notice that they never apologize for their behavior, usually cry and moan to emotionally blackmail the heroine if physical torture doesnt work. You can start with Sawan Biang.
I am more of a type 1 and 2 but I watched some of type 3 because of their awesome acting.
If you ever get to finish my list, please let me know and I will provide more.