The ratings I have on my list are purely subjective, based on the enjoyment and emotional impact I experienced while watching the dramas/movies. Any other claim would be misguided. I am not a professional critic, nor do I possess enough technical knowledge to objectively assess the merits of what I am watching.
Personal rating guidelines:
10: I thoroughly enjoyed it, and it deeply resonated with me emotionally throughout, perhaps even leading to tears or immense satisfaction with the ending.
9 - 9.5: I found it highly enjoyable, and with a slightly stronger emotional impact, it could have easily earned a perfect score of 10.
8 - 8.5: While I enjoyed it, there may have been a part or two that I didn't particularly like, or it didn't stand out as much overall.
6.5 - 7.5: It was a decent watch, but it lacked significant excitement or only had a few standout moments (the level of greatness varied among the dramas). This score also applies to dramas that started strong but fizzled out towards the end.
5 - 6: I felt indifferent or very bored while watching, or perhaps found some aspects of it annoying.
< 5: I rarely rated a drama below 5 because I typically stopped watching if it reached that level of dissatisfaction. As a personal rule, I never rated dramas I didn't finish. I believe that while enjoyment is subjective, labeling an art form as "bad" requires objectivity, which entails judging it from start to finish. However, I lack the patience and time to do so. For movies, a rating below 5 indicates that it was simply a movie I didn't enjoy at all but I managed to finish it due to the short running time.
As a caveat, I started watching K-dramas in 2002 so a lot of my ratings reflect what I felt after watching the dramas/movies at the time when they were airing, which probably would be different when put against today's standards. Additionally, I tend to gravitate towards character-driven stories over plot-driven ones.