This song... *sigh* So many feels. Too many to count. The lyrics of this song and the emotions behind it. The melody, the harmonies... everything about this song screams, I miss you. This is my favorite 2ne1 song and Let's not even forget to mention Dara's part, which is my favorite part in this song, btw. Whoever says she can't sing doesn't know a damn things about music and don't know how to appreciate the sweet and bell-like key that she sings in, like how Seungri does for Big Bang.
 

My second choice for this would definitely be Hurt by 2ne1, as well.