This is actually a really good idea! I've just looked through your PTW list and I don't think I've ever seen one as long as that!
I'll try and un-recommend some things, but the problem is when I dislike a drama I tend to drop it so take what I unrecommend with a pinch of salt (or is it sugar?). I'll still try!
I would unwatch these:
An Actor is an Actor (movie): TBH, I had no idea what was going on throughout. The plot is unclear, unless you read a summary first. It's a film about character development with no visible character development. The filming style is a hit or miss, and seems to be a miss for most.
Dal Ja's Spring: Some may disagree, but I found it too long. I got to a point (episode 17/22) where I just didn't care anymore and dropped it. I enjoyed the beginning but for me it dragged out and became tedious, so I would not watch it again given that chance.
My Secret Hotel: Keeping in mind I only got to episode 6/16. Started out fun. The synopsis says it's about a murder, but it's more about the romance. The murder loses importance, and I lost interest.
I clearly haven't seen enough of your PTW (or dropped too soon to comment on)! Please contradict my choices if you disagree, anyone! You have some great dramas in there as well!