hana kimi and host club
Marriage not dating 
Marriage Not Dating and My Girlfriend is a Gumiho
idk if it was the funniest but Oh My Ghost was really funny
The funniest k-drama I've watched so far has got to be Modern Farmer. Runaway idols becoming farmers to grow cabbages, in order to produce their album. This one literally had me dying like every episode. xD 
Gentleman's Dignity was pretty funny and i remember laughing at 7th Grade Civil Servant quite a bit
Please come back, Mister!
the last drama that had me cringing and yet laughing until my ribs hurt was Masters Sun and its a long time since a kdrama has made me laugh aaa lot. 
Modern Farmer - everything about this drama was hilarious.
Cunning Single Lady - the male lead had the funniest expressions/reaction to everything.
Kill Me Heal Me - Yuna.

Wild Romance, well written drama pretty hilarious!
The Greatest Love, Whats Up, Marriage Not Dating, My Girl, Coffee Prince, You Who Come From The Stars.
Just thinking of "Ding Dong!" with Dokko Jin makes me laugh! So far, it's The Greatest Love and The King of Dramas.
master's sun
rooftop prince
coffee prince
oh my ghost
you who came from the stars