I have 2 favorite characters whom I have this specific feelings for: Gil Tae-Mi and Yi Seong Gye

As you all know, Gil Tae-Mi is the guy who wears make-up like a gesaeng and fights like a real man should. He has stealth, awesome swords and great skills to match it up. I simply hate the fact that he belongs to the bad camp and does evil deeds because of his belief that the strong chew on the weak. Which is, at some point true and it does makes sense because he lived like that when he was under Yi In Gyeom's graces. But.. what was it that makes me love his character? I like his child like point of view at everything. His loyalty to his in-law. The way he fought with gusto. That carefree way he lived and did things in style. Those are Gil Tae-Mi's good points even if he was supposedly the bad guy. He sticks up to people he has vowed himself to be loyal to and that's a very rare thing you see with antagonists. So basically I will miss seeing his character on the following episodes because it means things will be more serious from episode 19 onward.

You might be wondering why the second person is Yi Seong Gye since he's one of the good guys, right? Why would I love to hate someone who's supposed to be an awesome character? Well for one, he's someone who can't decide properly due to his principles and he's someone easily swept by his emotions. He won't be a brilliant politician if not for the people around him so basically he's not a stand alone character. I also hate him for the fact that he has betrayed a person who trusted him like a brother because he was swept by his emotion for his family and not due to loyalty or his duty. He is a wishy-washy character compared to his son Bang Won. At least his son has his own thinking and he abides by it by hook or by crook regardless if it's good or bad. But then again, why do I love Yi Seong Gye despite everything I have mentioned? I have a soft spot for people who puts their family first before anything else. He decides for the benefit of his family and not simply for himself, so that makes up for my hate for him.

What about you guys? Do you have any Six Flying Dragons character you love to hate but can't help to love??? ^_^v
Gil Tae Mi is the obvious choice, but I'd go for Lee In Gyeom. His glare can be super creepy when he like lowers his head and glares to the side ._. but he is like that evil genius who keeps a smile and then when you leave he looks after you with a murderers glare ._. I just can't get inside his head and it's facinating to see him plot things.
I had put this in the main comments section before I saw this here. I absolutely can't believe Park Hyeok Kwon did not win an award for his portrayal of Gil Tae Mi/Gil Seon Mi. Hyeok Kwon is by far the most captivating and enjoyable character to the series thus far. He's awesome. Tae Mi's death was one of the saddest bad guy deaths I've ever or in a great long time remember. I hated seeing him go down.

Judging from your comments, Gil Tae Mi must be well liked. I honestly didn't know others would quite take to him like I did. Yes he was a bad guy, but even as a bad guy his loyalty. Some of his comments from while on the run before the final battle were so sweet in his way. Like being grateful for his time and the opportunities he got and the level he reached. 
I HATEF seeing him get killed, but he did get the proper send off. The build up to his death and displaying his fighting skills. It was awesome. Still so sad though.