Oh, missed the words love triangle... Already deleted my previous answer. Maybe (bad ending used to be a trend for such case, so...):
3. Lovers in Paris
4. Farewell Firefly
5. Time Between Dog and Wolf
6. Snow Angel

newbiefan:
It has been 24 hours so may I propose another topic?
10 dramas with an opening scene (ep. 1 the first story bit, not the credits bit) that grabs your attention. It can be funny, dramatic, confusing, something else. It can be a small detail or big and in your face. All it needs to do is jump out and grab your attention.
My Sweet Mobster - So many details. The voice over guy's way of talking and how it all sounds (da dit dit, da dit dit, da dit dit) with the old school music and microphone sound, the hand on the head, sepia coloring.
4. Human Vapor - a professor's body blown up into pieces in the sky
5. The Yarns - a body that was found has his internal organ full of weaver ants eating him from inside
6. Yumi's Cells S3 - love at first sight + unexpected coldness (the beginning of enemies to lovers trope).