-Cunning Single Lady | ML treats FL bad at first but he has a reason for hating her. He does treat her much better later on and falls in love with her again. His apology comes almost at the end of the series, when he learns the reason FL left him in the first place.
-What's wrong with secretary Kim | this drama is very light and cliché, but there are a lot of moments when ML says something mean to FL then struggles to apologize (but he does).
-Cheese in the trap | He starts out as FL's bully then develops feelings for her. He does apologize later on, but keep in mind that this romance isn't fluffy. On the contrary, it's quite dark.
-Falling for innocence | he starts out being a jerk and changes as he falls for her. Don't recall if he ever apologized, though. It's been a while since I finished this one.
-Oh my Ghostess | ML has moments when he gets frustrated with the female lead and later regrets it.
-Wok of Love | same as above, though his self reflection and regret is more evident.
Fated to Love You | has various scenes where ML says/does something he later regrets and apologizes for.