Sometimes in Korean dramas, they play instrumental versions of Western music. I was pretty surprised when I heard:

Blue Light, Red Light - Harry Connick, Jr.

Breakfast at Denny's - Combustible Edison (!)

Also during a climactic moment in one drama, I may or may not have heard a haunting rendition of the Inspector Gadget theme song playing softly in the background.

Also, at around 2:30 a.m., Korea turns from ultra-harmless, kid-friendly programming to the all porn network.