I recommend Penthouse only if you watch the crime thriller genre as it is a serious kdrama. Watching this drama was like a roller coaster ride. It had many unexpected plot twists. The cinematography, soundtracks, BGM and the setting was exceptional! The cast was amazing with their acting. I especially loved Choen Seo Jin and Ju Dan Tae's acting. Yes some parts of the plot were illogical but hey it's a kdrama! 😂 The first half of season 1 is a little slow paced however if you keep watching, this series will keep you hooked till the end of season 3. The story conveys the reality of this materialistic world where some rich people chase after money, status and power and will go to any lengths to keep them.
SPOILER ALERT
The only part I didn't like about Penthouse is that almost all the main characters both protagonists and antagonists were dead by the end of the series.
PS: I finished watching Penthouse long back in January 2022. I just got reminded of the drama because I listen to the title theme OST often and I felt like writing a review.