I laughed ALOT in Hana KImi (j-version) but it is a gender bender so if it's not your cup of tea, it might just seem totally ridiculous rather than funny.
Also the greatest love. Cha Seung Won and Gong Hyo Jin are the perfect comic pair.
Beautiful Gong Shim (currently airing, the 2 main characters are such dorks... and the guy is SO lovely =w=) Marriage, Not Dating (probably the funniest kdrama I had the chance to watch...)