I looked through your list and we've watched a lot of the same dramas and rated them pretty similarly. Since we seem to have similar taste, here are some of the dramas I've also watched that I rated highly but don't seem to have made your list yet in no particular order. I wrote reviews for some, so I've added that link as well if you're interested (the ones that have reviews are starred).
Oh My Ghostess - Park Bo Young is fantastic, but Kim Seul Gi is one of my favorite actresses and this is one of the few dramas where she has a lead role.
Splash Splash LOVE - Drama special but so good! Kim Seul Gi as FL, ML is very charismatic, and Ahn Hyo Seop in a great supporting role.
A Piece of Your Mind* - Again, like most of my recommendations here, I really like all the leads for this drama. A slower contemplative plot, but still good! Since you liked Something in the Rain, I think you would like this as well.
XX - Short web drama but with great cinematography! Something about watching them mixing drinks is very relaxing.
Coffee Prince - Gong Yoo and Yoon Eun Hye, so basically A Classic (TM). Definitely has it's highs and lows but I've rewatched many times. It's kind of outdated?
Her Private Life - Park Min Young and Kim Jae Wook have great chemistry, and the plot line is different and relatable!
When the Weather Is Fine* - Gives me warm and cozy vibes. Honestly, I'll watch anything with Park Min Young, but Lee Jae Wook really stood out in this drama.
My ID is Gangnam Beauty* - There were parts of this drama that I didn't like, but there were parts that I loved. I think it has an important message. Kwak Dong Yeon really stood out in this drama for me.
My Secret Romance - Leads have great chemistry; kind of cliche but still good! The ML Sung Hoon is like the most relatable person IRL lmao.
Happy Watching!