The funniest kdrama I’ve ever watched is Heard it Through the Grapevine but it entirely depends on your sense of humor whether it’d suit you. It’s a black comedy the humor of which is rooted in social commentary (sometimes acerbic, sometimes silly).
Prison Playbook & Reply Series are extremely funny (well, to me) as well, I listed them together because they come from the same team.
I haven’t actually seen Chief Kim or Welcome to Waikiki but everyone seems to list them when asked about best comedic dramas.
Kill Me Heal Me has really funny moments, Oh My Ghostess too.
Hong Sis dramas are really great when it comes to comedy, esp My Girl & The Greatest Love.