Wheesung - Insomnia

http://www.jpopasia.com/lyrics/19539/wheesung/insomnia.html

Wheesung - Insomnia MV (english subbed)

http://www.jpopasia.com/lyrics/19539/wheesung/insomnia.html

Hangul, romanji and translated lyrics can be found in the above link.
I think english and korean versions are quite similar. However, I love the korean version more. =P

It's very addictive, won't get bored by the melody.