Dramas with great OSTs

Only dramas with great OSTs in this list. They are in order of which I think has the best.

Requirements for being a great OST must have at least 2 out of the following four:

-have at least 1-2 genuine bangers

-have a fresh vibe or unique sound (Instrumental background music)

-have songs that fit the mood or help tell the story perfectly

-have quality original scores

The top five dramas must have 3 out of 4.

***There seems to be a trend that BL's tend to always have a pretty good sound track