Big - Even though I love Gong Yoo, knowing how badly that drama turned out makes me refuse to waste my time on it.
Pinocchio - no matter how i love lee jong suk and how many people said that it is good, i just cant bring myself to watch another drama with park shin hye+poor girl+candy girl+love triangle formula. That's just really too much for me.
oh my venus 
it's physically impossible for me to even consider watching it
Shopping king louie, coffee prince, cheese in the trap and innocent man
I was actually getting curious about Boys Over Flowers, but my better judgment stopped me ;p
I refuse to complete Goblin, DOTS, Coffee Prince and Healer...
Boys over flowers, Heirs. Even though I love Lee Minho :) I also didnt watch Cheese in trap, and it was everywhere but I couldnt...
I refuse to watch "Tanaka Afro" 
It's felt very bias and BS! I just couldn't... 
I refuse to watch Winter Sonata, 1 Litre of Tears, Stairway to Heaven, I'm Sorry, I Love You, A Love To Kill and Koizora because they're sad af and (I think) mostly of them doesn't have a happy ending and I refuse to watch anything that doesn't have a happy ending. lol

I also refuse to watch any drama that Gu Hye Seon is in, except for Boys Over Flowers, that I'm going to finish it one day, I hope, and Angel Eyes, because of Lee Sang Yoon.
Moon Lovers: Scarlet Heart Ryeo. NOT because it's bad or anything. But I don't like the kind of ending it has, so that's why
nirvana of fire..I don't know why... 
Mirror of the Witch.
Boys over flowers. Hana Yori Dango was my first drama ever, I loved it. I know I'd find everything wrong in Boys over flowers because of that
I refuse to watch any doctor related drama's, because I don't like that sorta genre.
City Hunter

I heard it is similar to Healer - and I love Healer - but still I really don't like Lee min ho.