Ive tried watching this drama 3 times but I always drop it after 1-3 episodes because I can't stand the lead guy. But everyone seems to rate  it high and it often comes up in recommendations, anyways does a miracle happen or something that makes the lead guy tolerable?

This is one of my favourite dramas.It has such a great plot and evil nemesis.I have always quite liked the lead but surely one character can't ruin the the whole drama there is more to the story than one guy.
Do you not like the actor or is it the character?
Saying all that though if you have tried it three times already then maybe it just isn't for you.We all have different tastes and I have dramas I've watched and really enjoyed while others have hated.
Maybe try watching the first 5 episodes and if it's still bad give up and watch something else there are plenty of dramas to watch.
Maybe you like more mature male leads (I do too). In ep 1-3 they really emphasise the playboy immature aspect of the Prince. Note - he's the crown prince, not the king as all the subtitles say. He rules nothing, he doesn't want to rule and his playboy ways are deliberate because he doesn't want to be king. All this is so that when he matures later on, you will see the development and the truly great backbone that he has. Also, this drama is carried by the characterizations of Eun Shi Kyung and Kim Hang Ah. Those characters are the pillars by which the prince matures later.

If you want specific spoilers, drop me a line. :)
I think this drama is highly overrated. I dropped it, but at the insitance of a friend, I picked it back up again. I forced myself to complete it. I think I rated it a 6 or 7. It has a few moments but for the most part I found it draggy and boring. I have seen worse dramas, though.
You aren't supposed to like the male lead at first. His development into a responsible adult is part of the plot. I personally loved this series. 
Before this the only dramas I watched with this lead actor (Lee Seung Gi) were My Girlfriend is a Gumiho and Shining Inheritance. It was not that I didn't like him. He played his parts well and the dramas were nice and all. But it was The King2Hearts that made me recognize his skills fully. The first few episodes his character is an ass, as to say. Can't deny it. But while watching you can see him mature step by step. It's worth to watch his developments.

If you trully don't like the actor and all, don't try it. I, for myself, can't get through a drama and fully enjoy it if I don't like the actors. May the drama itself be a masterpiece and all. It just doesn't work for me in that case.
If it's about the character and not the actor himself then don't worry cause he'll change and become a man once he has to ..
For me that was the best role Lee Seung Ki ever acted until now and I even still remember his character's name; Lee Jae Ha, knowing that I rarely remember any names of the characters once i finish a drama!
But still, you may not like it .. it's not a rule that you'll like a drama just because everyone else liked it.. There are a lot of dramas that made a huge succes and i'm still wondering why! :D

Sick with it, he grows up and as I have written. This is a rare dram that gets better a it goes on! I promise, everything with get so much better.

In my opinion, his character gets better, but I have had it on hold because the female lead gets more annoying further on in the series.