Mischievous Kiss was definitely worth the watch and since that's the only one I've watched out of the other ones you wrote about, I'll only talk about this one! I did enjoy watching it and I'm happy that it was one of my first dramas, but I'd have to agree with you. Even though Kotoko was very cute, it felt like she crossed lines multiple times. I guess I'm just too used to characters like her (and honestly a little tired, but it's easy to avoid lol). I also never understood how the people around her encouraged her to do whatever she wanted, too. The whole series was really enjoyable, especially when it comes to giving you the cute scenes that you want!
I've enjoyed lots of episodes that I can't name off the top of my head, but I really enjoyed the episode with shinee because it made laugh since they were so chaotic! It definitely cheered me up (: It was a good combo of people, I should say