what happens to my family 53 eps
I'm currently finishing Ugly alert too x) can't believe I watched that much episodes already o_o what have I done with my life haha 
but it's such an amazing drama Elisa, those were hours full of joy :)
Potato Star 2013, 120 episodes. 
i don't watch drama above 20 ep.but I watched''BOYS OVER FLOWER''.I think it's my longest.but i didn't watch all the ep.i watched ep1-6,11,14,25
Definitely EMPEROR WANG GUN, with 200 Episodes, 60 minutes each episodes, if tv version could be more than 200 episodes. so, yeah this one is definitely the longest korean drama ever.
Potato Star 120 episodes but I did fast forward a lot.. 
Bridal Mask! I think it was almost 40 episodes.
The longest one I've watched so far is Bridal Mask. Or maybe Warrior Baek Dong Su, I can't remember how many episodes were in that one.
My Love, Madame Butterfly (51 episodes).
Six flying Dragons 50 episodes
Pure 19/ Pure in Heart- 167 episodes. Soooo good. 
Pink Lipstick - 150 episodes.

I cannot even remember how i did that ^^