There is a lot amazing dramas on your list. I recommend Cheese in the Trap, Eulachacha Waikiki and Signal first because they are my favorite. But you should definitely watch Go Back Couple and You who came from the stars too.
I honestly haven't watched all that many in your PTW, but Duel would be the drama of those I know that I'd say to give a try. I personally loved it, but that first episode does start a little slow.
