Based from the title, I'm looking for dramas that were a national craze or atleast had high ratings during its tv run and deserved it. 

around the time i still watched it alot, more 'well known' dramas such as 'goblin', 'descendants of the sun', were airing. if they deserved the hype, i'm not sure though.

Reply 1988 (2015/2016) - had the highest ratings in cable tv  that time and currently #4 behind Sky Castle (2018), World of the Married (2020) and Crash Landing on You (2019)