The Cardigans. "Lovefool." First Band On The Moon, Universal Music AB, 1996.
There were so many great tracks on the Romeo + Juliet soundtrack, but this one takes the cake for having the sweetest, most smile-inducing, can't-help-but-make-you-get-on-the-dance-floor, happy sound.
Music video by The Cardigans performing Lovefool. (C) 1996 Universal Music AB http://vevo.ly/yB3FrV