Tbh, there have been so many good ones but Dae Jang Geum is a serious throwback to my childhood. I LOVED WATCHING IT WITH MUM. As for more recent ones... I like medical/crime/mystery kinda dramas idk.
Emergency Couple was pretty good it had jihyo in it <3
Goblin !!! Like the most recent one that had everyone going crazy i think
W - Two World LEE JONG SUK <3 ALSO PRETTY INTERESTING STORY 
DREAM HIGH - oldie but idk i still love it.

i only finished watching goblin, weight lifting fairy kim bok joo and Hwarang so :~))))) Yes top 3 in that order.

HWARANG OMFG MY BAE THERE

IM WATCHING korean odyssey and its so GOOD

Winter Sonata, My Love from the Star and drama about politics (forgot the title LOL)

Weightlifting Fairy was a fun drama to watch to, they were all cute in the drama and their outfits are to die for. 
I also loved "While You Were Sleeping" - it has an interesting storyline and Suzy's acting is not bad in it, so I'm down for it. 
Innocent Defendant is a nice drama too. 

i only watched 2 kdramas before in my life

DOTS AND WEIGHTLIFTING FAIRY !! AND W !!!

EXO NEXT DOOR OMG