Signal stopped airing but it is the best drama of this year (for me). 
I'm watching signal currently. Didn't really grab my attention at first but I think they are saving the best but till last. It's deffo a 10 rating from me upto  episode 12

It's obviously not airing anymore but just thought I'd say as you should try it. I don't watch airing dramas so can't comment haha
No more Signal, sadly. :/

Now watching DOTS, Come back Ajusshi (catching up, currently finished ep 6) and Goodbye Mr. Black (watched 4 eps in a go). As I started DOTS and GMB without any expectations, I'm enjoying them more than I thought I would. All three are Wed-Thurs dramas but are tonally different so that's nice.