I really love and enjoy those shows.

[Don't mind my list. Thank you!]
Is your list up to date?
I'd recommend you to watch the currently airing "Beautiful Gong Shim" - both of them are quite funny and such dorks... Especially the main lead, I think you can't help but love him. :)
Both leads from Salaryman.
The whole gang from Flower Grandpa Investigation Unit.
Shin Min Ah's characters in My Girlfriend is a Gumiho and Arang and the Magistrate.
The team from Seonam Girls High School Investigators.
Marriage, not dating ^^
large cast dramas that have interesting, likable characters:
Bromance
Modern Farmer
Moon River
My Amazing Boyfriend
The Crossing Hero
Tomorrow's Cantabile
Vampire Detective (ok, not that big of a cast, but the three leads have such an adorable, awesome bond)
Dramas with many funny, interesting characters:

Hana Kimi (beats everything else)
Atashinchi no danshi
Reply 1988 (& 1997 too)
Love Shuffle
Yamada kun to nananin no Majo
Sugarless
Pinocchio (The reporters are funny awesome)
Ex-Girlfriend Club
Cheer Up

Not funny but interesting & memorable:
White Christmas
Shut Up
Incomplete Life

Recent ones like DOTS, Come Back Ajusshi, My Little Baby also fit, I think.

Jung Kyung Ho's character in Falling for Innocence 
Ahn Dan Tae from currently airing drama, Beautiful Gong Shim and also Gong Shim lol
The Trio from Twenty(Movie)
Cha Jung Woo from Cunning Single Lady
That CEO with the laugh aka the main lead from Fated to Love You

I second Please Come Back Ajusshi
Others:
Date - Koi to wa Donna Mono Kashira
Kokoro ga Pokitto ne
Kaitou Tantei Yamaneko
Love Shuffle
The Lover
Oh Hae Young Again
Reply19(97-94-88)
I Remember You
Page Turner
Healer
I hear your voice, has great main characters, the supporting cast is also quite loveable & funny
Splash splash Love (webdrama) has really cute and loveable main characters. 

These have been suggested already, but I'll mention them again because they're so great:
Hana kimi (first Japanese version)
Sassy Go Go/Cheer Up
Reply 1997
Page Turner (webdrama)