Hi, my sweetheart- He goes from a nerdy mushroom-haired sweet guy to a suave player.
Pinocchio- His hair is a mess, but when he gets a haircut he's omg. He played the fool most of his life but, in reality he is genius smart. He becomes a reporter so, he has to change his appearance.
Flower Boy Next Door- He changes his hair color at the very end. He's also very nerdy and playful and kinda becomes more mature for the female's sake. There's a make-over scene that is really funny in which the three males go and get dressed up for an "undercover mission".
Hwarang- The male lead goes from dirt poor( and dressed for it), to a great warrior and dressed for it.
Introverted Boss- His makeover is more personality-wise.
Queen In Hyun's man- He time travels so he has a old to modern makeover. He even cuts his long Joseon-era hair to a short modern style.
Shopping King Louie- He loses his memory and gets lost so he's hair and clothes are different. When he goes back to his family, even before recovering his memory, he dresses better.
The Bride of Habaek- He looks very different from godlike to human like. His hair and make-up is the biggest change, although his clothes are obviously very different.
The Legend of the Blue Sea- Not really a makeover but, he's a scammer so he changes appearance constantly.